60297-9 - operator's manual - o-235 and o -...

OPERATOR'SMANUAL

Lycoming

0-235 and 0-290 SERIES

AIRCRAFT ENGINES

4th Edition January 1988

Approved by F.A.A.

Part No. 60297-9

LYCOMING OPERATOR'S MANUAL

ATTENTION

OWNERS, OPERATORS ANDMAINTENANCE PERSONNEL

This operator's manual contains a description of the engine, itsspecifications, and detailed information on how to operate and maintainit. Such maintenance procedures that may be required in conjunctionwith periodic inspections are also included. This manual is intended foruse by owners, pilots and maintenance personnel responsible for care ofAvco Lycoming powered aircraft. Modifications and repair proceduresare contained in Avco Lycoming overhaul manuals; maintenance person-nel should refer to these for such procedures.

SAFETY WARNING

Neglecting to follow the operating instructions and to carry outperiodic maintenance procedures can result in poor engine performanceand power loss. Also, if power and speed limitations specified in thismanual are exceeded, for any reason, damage to the engine and personalinjury can happen. Consult your local FAA approved maintenance facili-ty.

SERVICE BULLETINS, INSTRUCTIONS AND LETTERS

Although the information contained in this manual is up-to-date attime of publication, users are urged to keep abreast of later informationthrough Avco Lycoming Service Bulletins, Instructions and Service Let-ters which are available from all Avco Lycoming distributors or from thefactory by subscription. Consult the latest edition of Service Letter No.L114 for subscription information.

SPECIAL NOTE

The illustrations, pictures and drawings shown in this publication aretypical of the subject matter they portray; in no instance are they to beinterpreted as examples of any specific engine, equipment or partthereof.

TEXTRON LYCOMING OPERATOR'S MANUAL

IMPORTANT SAFETY NOTICE

Proper service and repair is essential to increase the safe, reliableoperation of all aircraft engines. The service procedures recommendedby Textron Lycoming are effective methods for performing serviceoperations. Some of these service operations require the use of toolsspecially designed for the task. These special tools must be used whenand as recommended.

It is important to note that most Textron Lycoming publications con-tain various Warnings and Cautions which must be carefully read inorder to minimize the risk of personal injury or the use of improper ser-vice methods that may damage the engine or render it unsafe.

It is also important to understand that these Warnings and Cautionsare not all inclusive. Textron Lycoming could not possibly know,evaluate or advise the service trade of all conceivable ways in which ser-vice might be done or of the possible hazardous consequences that maybe involved. Acordingly, anyone who uses a service procedure must firstsatisfy themselves thoroughly that neither their safety nor aircraft safe-ty will be jeopardized by the service procedure they select.

(LIMITED)NEWAND REMANUFACTURED

RECIPROCATING AIRCRAFT ENGINE

WHAT TEXTRON LYCOMING PROMISES YOU

Textron Lycoming warrants each new and remanufactued reciprocating engine sold by it to be free from defects inmaterial and workmanship appearing within one (1) year from the date of first operation, excluding necessary aircraftacceptance testing The date of first operationmust not exceed two (2) years from the date ofshipment from TextronLycoming.

Textron Lycoming's obligation under this warranty shall be limited to its choice of repair or replacement, on anex-change basis, of the engine or any part of the engine, when Textron Lycoming has determined that the engine is defectivein material or workmanship. Such repair or replacement will be made by Textron Lycoming at no charge to you. TextronLycomig will also bear the cost for labor in connection with the repair or replacement as provided in TextronLycoming's then current Removal and Installation Labor Allowance Guidebook.

In addition, if Textron Lycoming determines that the engine proves to be defective in material or workmanship duringthe period until the expiration of Textron Lycoming's recommended Time Between Overhaul (TBO), or two (2) yearsfrom the date of first operation, whichever occurs first, Textron Lycoming will reimburse you for a pro rata portion of thecharge for the repair or replacement (at its choice) with Textron Lycoming parts,ofparts required tobe repairedorre-placed, or a replacement engine, if it determines that engine replacement is required. Textron Lycoming's obligationduring the proration period extends to major parts of the engine, which are limited to crankcase, crankshaft, camshaft,cylinders, connecting rods, pistons, sump, accessory housing and gears. The proration policy does not extend to labor orto accessories, including but not limited to magnetos, caburetors or fuel injectors, fuel pumps, sarers, alternators andturbochargers and their controllers.

Any engine or part so repaired or replaced will be entitled to warranty for the remainder of the original waranty period.

YOUR OBLIGATIONS

The engine must have received normal use and service. You must apply for warranty with an authorized TextronLycoming distributor within 30 days of the appearance of the defect in material or workmanship.

Textron Lycoming's warranty does not cover normal maintenance expenses or consumable items. The obligations onthe part of Textron Lycoming set forth above are your exclusive remedy and the exclusive liability of Textron Lycoming.This warranty allocates the risk of product failure between you and Textron Lycoming, as permitted by applicable law.

Textron Lycoming reserves the right to deny any warranty claim if it reasonably determines that the engine or part hasbeen subject to accident or used, adjusted, altered, handled, maintained or stored other than as directed in your operator'smanual, or if non-genuine Textron Lycoming parts are installed in or on the engine and are determined tobeapossiblecause of the incident for which the warranty application is filed.

Textron Lycoming may change the construction of engines at any time without incurring any obligation to incorporatesuch alterations in engines or parts previously sold.

THIS LIMITED WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL. OTHER WARRANTIES AND REPRESEN-TATIONS, EXPRESS OR IMPLIED OR STATUTORY, WHETHER WRITTEN OR ORAL, INCLUDING BUT NOTLIMITED TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE,AND ANY IMPLIED WARRANTY ARISING FROM ANY COURSE OF PERFORMANCE OR DEALING ORTRADE USAGE. THIS WARRANTY IS ALSO IN LIEU OF ANY OTHER OBLIGATION, LIABILITY, RIGHT ORCLAIM, WHETHER IN CONTRACT OR IN TORT, INCLUDING ANY RIGHT IN STRICT LIABILITY INTORT OR ANY RIGHT ARISING FROM NEGLIGENCE ON THE PART OF TEXTRON LYCOMING, ANDTEXTRON LYCOMING'S LIABILITY ON SUCH CLAIM SHALL NNO CASE EXCEED THE PRICE ALLO-CABLE TO THE ENGINE OR PART WHICH GIVES RISE TO THE CLAIM.

LIMITATION OF LIABILITY

IN NO EVENT, WHETHER AS A RESULT OF A BREACH OF WARRANTY, CONTRACT OR ALLEGED NEG-LIGENCE, SHALL TEXTRON LYCOMING BE LIABLE FOR SPECIAL OR CONSEQUENTIAL OR ANY OTHERDAMAGES, INCLUDING BUTNOT LIMITED TOLOSSOF PROFITSOR REVENUES, LOSS OF USE OF THEENGINE OR COST OF A REPLACEMENT.

No agreement varying this warranty or Textron Lycoming's obligations under it will be binding upon TextronLycoming unless in writing signed by a duly authorized representative of Textron Lycoming.

Effective October 1, 1995 Revision "J'

Textron LycomingWilliamsport, Pennsylvania

WARRANTY(LIMITED)

REPLACEMENT PART - RECIPROCATING AIRCRAFT ENGINE


Textron Lycoming warrants each new reciprocating aircraft engine replacement pat sold by it to be free from defectsinmaterial and workmanship appearing within one (I) year from its date of first operation. The date of first opera-tion. must not exceed two (2) years from the date of shipment from Textron Lycoming.

Textron Lycoming's obligation under this warranty shall be limited to its choice of repair or replacement, on an ex-change basis, of te replacement part, when TextronLycoming has determined that the pan is defective in material orworkmanship. Textron Lycoming will also reimburse you for the costs for labor in connection with the repair or replace-ment as provided in Textron Lycoming's then current Removal and Installation Labor Allowance Guidebook

Any part so repaired or replaced will be warranted for the remainder of the original warranty period.

YOUR OBLIGATIONS

The engine in which the replacement part is installed must have received normal use and service. You must apply forwarranty with an authorized Textron Lycoming distributor within 30 days of the appearance of the defect in material orworkmanship.

Textron Lycoming's warranty does not cover normal maintenance expenses or consumable items. The obligations onthe part of Textron Lycoming set forth above are your exclusive remedy and the exclusive liability of Textron Lycoming.This warranty allocates the risk of product failure between you and Textron Lycoming, as permitted by applicable law.

Textron Lycoming reserves the right to deny any warranty claim if it reasonably determines that the engine or part hasbeen subject to accident or used, adjusted, altered, handled, minained or stored other than as directed in your operator'smanual, or if non-genuine Textron Lycoming parts are installed in or on the engine and are determined to be a possiblecause of the incident for which the warranty application is filed.

Textron Lycoming may change the construction of engines at any time without incurring any obligation to incorporatesuch alterations in engines or pars previously sold.

THIS LIMITED WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES AND REPRESEN-TATIONS, EXPRESS OR IMPLIED OR STATUTORY, WHETHER WRITTEN OR ORAL, INCLUDING BUT NOTLIMITED TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE,AND ANY IMPLIED WARRANTY ARISING FROM ANY COURSE OF PERFORMANCE OR DEALING ORTRADE USAGE. THIS WARRANTY IS ALSO IN LIEU OF ANY OTHER OBLIGATION, LIABILITY, RIGHT ORCLAIM, WHETHER IN CONTRACT OR IN TORT, INCLUDING ANY RIGHT IN STRICT LIABILITY INTORT OR ANY RIGHT ARISING FROM NEGLIGENCE ON THE PART OF TEXTRON LYCOMING, ANDTEXTRON LYCOMING'S LIABILITY ON SUCH CLAIM SHALL IN NO CASE EXCEED THE PRICE ALLO-CABLE TO THE ENGINE OR PART WHICH GIVES RISE TO THE CLAIM.


IN NO EVENT, WHETHER AS ARESULT OF A BREACH OF WARRANTY, CONTRACT OR ALLEGED NEG-LIGENCE, SHALL TEXTRON LYCOMING BE LIABLE FOR SPECIAL OR CONSEQUENTIAL OR ANY OTHERDAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFTS OR REVENUES, LOSS OF USE OF THEENGINE OR COST OF A REPLACEMENT.


Effective October 1, 1995 Revision "J"


I

. Lycoming

WARRANTY(LIMITED)

OVERHAULEDRECIPROCATING AIRCRAFT ENGINE


Textron Lycoming warrants each overhauled reciprocating engine sold by it to be free from defects in material andworkmanship appearing within one (1) year from the date of first operation, excluding necessary aircraft acceptancetesting. The date of first operation must not exceed two (2) years from the date of shipment from Textron Lycoming.

Textron Lycoming's obligation under thi:; warranty shall be limited to its choice of repair or replacement, on an ex-change basis, of the engine or any part of the engine, when Textron Lycoming has determined that the engine is defectivein material or workrmanship. Such repair or replacement will be made by Textron Lycoming at no charge to you. TextronLycoming will also bear the cost for labor in connection with the repair or replacement as provided in TextronLycoming's then current Removal and Installation Labor Allowance Guidebook.

Any engine or part so repaired or replaced will be entitled to warranty for the remainder of the original warranty period.

YOUR OBLIGATIONS

The engine must have received normal use and service. You must apply for warranty with an authorized TextronLycoming distributor within 30 days of the appearance of the defect in material or workmanship.

Textron Lycoming's warranty does not cover nominal maintenance expenses or consumable items. The obligations onthe pan ofTextron Lycoming set forth abovt are your exclusive remedy and the exclusive liability of Textron Lycoming.This warranty allocates the risk of product failure between you and Textron Lycoming, as permitted by applicable law.

Textron Lycoming reserves the right to deny any warranty claim if it reasonably determines that the engine or part hasbeen subject to accident or used, adjusted, altered, handled, maintained or stored other than as directed in your operator'smanual, or if non-genuine Textron Lycoming parts are installed in or on the engine and are determined to be a possiblecause of the incident for which the warranty rpplication is filed.

Textron Lycoming may change the construction of engines at any time without incurring any obligation to incorporatesuch alterations in engines or parts previously sold.

THIS LIMITED WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES AND REPRESEN-TATIONS, EXPRESS OR IMPLIED OR STATUTORY, WHETHER WRITTEN OR ORAL, INCLUDING BUT NOT <LIMITED TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE, <AND ANY IMPLIED WARRANTY ARISING FROM ANY COURSE OF PERFORMANCE OR DEALING ORTRADE USAGE. THIS WARRANTY IS ALSO IN LIEU OF ANY OTHER OBLIGATION, LIABILITY, RIGHT ORCLAIM, WHETHER IN CONTRACT O IN TORT, INCLUDING ANY RIGHT IN STRICT LIABILITY INTORT OR ANY RIGHT ARISING FROM NEGLIGENCE ON THE PART OF TEXTRON LYCOMING, ANDTEXTRON LYCOMING'S LIABILITY ON SUCH CLAIM SHALL IN NO CASE EXCEED THE PRICE ALLO-CABLE TO THE ENGINE OR PART WHICH GIVES RISE TO THE CLAIM.


IN NO EVENT, WHETHER AS A RESULT OF A BREACH OF WARRANTY, CONTRACT OR ALLEGED NEG-LIGENCE, SHALL TEXTRON LYCOMING BE LIABLE FOR SPECIAL OR CONSEQUENTIAL OR ANY OTHERDAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS OR REVENUES, LOSS OF USE OF THEENGINE OR COST OF A REPLACEMENT.


Effective October 1, 1995 Revision J"


I

i

i


TABLE OF CONTENTS

SECTION 1

SECTION 2

SECTION 3

SECTION 4

SECTION 5

SECTION 6

SECTION 7

SECTION 8

DESCRIPTION

SPECIFICATIONS

OPERATING INSTRUCTIONS

PERIODIC INSPECTIONS

MAINTENANCE PROCEDURES

TROUBLE-SHOOTING

INSTALLATION AND STORAGE

TABLES

Page

1-1

2-1

3-1

4-1

5-1

6-1

7-1

8-1

5.

314 Right Fmnt View - 0-235-C, 0-290-D

Rear View - O-290-D2


DESCRIPTION

Page

General ................................................ 1-1Cylinders .............................................. 1-1Valve Operating M echanism ............................. 1-1Crankshaft ............................................ 1-2Crankcase ............................................. 1-2Oil Sum p .............................................. 1-2Connecting Rods ...................................... 1-2P isto n s . ... .. .... .. ... ... . ... .. .. .. . .... .. .. .... ... .... 1-2Accessory Housing ..................................... 1-2Gears ................................................. 1-2Cooling System ........................................ 1-3Lubricating System ..................................... 1-3Induction System ....................................... 1-3Ignition System ........................................ 1-3Table of M odels ........................................ 1-4


0-235 AND 0-290 SERIES SECTION 1

SECTION 1

DESCRIPTION

The Lycoming 0-235 series, 0-290-D series and 0-290-D2 seriesengines are four cylinder, direct drive, horizontally opposed, wet sump,air-cooled models.

In referring to the location of the various engine components,the partsare described in their relationship to the engine as installed in conven-tional airframes. Thus the power take-off end is considered the front andthe accessory drive section the rear. The sump section is considered thebottom and the opposite side of the engine where the shroud tubes arelocated is the top. References to the left and right side of the engine aremade with the observer facing the rear of the engine. Thus the frontcylinder on the left bank is number 2 and the rear cylinder is number 4.The front cylinder on the right bank is number 1 and the rear cylinder isnumber 3. The direction of rotation for accessory drives is determined bythe observer facing the drive pad. The direction of rotation of thecrankshaft, viewed from the accessory end of the engine is clockwise.

Cylinders - The cylinders are of conventional air-cooled constructionwith the two major parts, head and barrel, screwed and shrunk together.The heads are made from an aluminum alloy casting with a fully machin-ed combustion chamber. The barrels, which are machined from chromenickel molybdenum steel forgings with deep integral cooling fins, areground and honed to a specified finish.

The valve rocker shaft bearing supports and the rocker box housingare cast integrally with the head. The valves are cooled by means of finswhich completely surround the area of the exhaust valve and portions ofthe intake valves, Valve guides and valve seats are shrunk into machin-ed recesses in the head.

Valve Operating Mechanism - The valve operating mechanism is locatedon the top side. The camshaft is located parallel to and above thecrankshaft and operates in aluminum bearings. The camshaft in turn ac-tuates the valves by means of tappets. The valve rockers are supportedon full floating, steel shafts. The valve springs bear against hardenedsteel seats.

1-1


SECTION 1 0-235 AND 0-290 SERIES

NOTE

Hydraulic tappets which automatically keep the valve clearance at zeroare employed on the 0-290-D2 series engines while solid tappets areemployed on the 0-235 and 0-290D series. Proper valve clearance on thelatter models is maintained by means of an adjusting screw located inthe valve rocker.

Crankshaft - Made from a chrome nickel molybdenum steel forging. Allbearing surfaces are nitride hardened. The expansion plug in thecrankshaft must be removed on those models employing a two positionhydro control or variable pitch propeller.

Crankcase - Crankcase assembly consists of two reinforced aluminumalloy castings divided at the center line of the engine and fastenedtogether by bolts and nuts. The mating surfaces of the crankcase arejoined without the use of a gasket, and main bearing bores are machinedfor use of precision type main bearing inserts.

Oil Sump - Incorporates an oil suction screen, carburetor mounting pad,the intake riser and intake pipe connections. The fuel-air mixture, as itpasses through the riser, is vaporized by the heated oil that surroundsthe riser.

Connecting Rods - Made in the form of "H" sections from alloy steelforgings. They have replaceable bearing inserts in the crankshaft endsand split type bronze bushings in the piston ends. The bearing caps onthe crankshaft ends are retained by means of two bolts and nuts througheach cap.

Piston - Machined from an aluminum alloy. Two compression rings andan oil regulating ring are employed on all pistons. In addition, the 0-235series employs an oil scraper ring below the piston pin. The piston pin isof the full floating type with a plug located at each end to prevent the pinfrom touching the cylinder wall.

Accessory Housing - Made from an aluminum casting and is fastened tothe rear of the crankcase and the top rear of the oil sump. It forms ahousing for the oil pump and the various accessory drives.

Gears - Are of the conventional type and precision machined, hardenedto insure long life and satisfactory operating qualities.



Cooling System -These engines are designed to be cooled by air pressureactuated by the forward speed of the aircraft. Close fitting baffles buildup a pressure and force the air through the cylinder fins. The air is thenexhausted through gills or augmentor tubes usually located at the rearof the cowling.

Lubrication System - The full pressure wet sump lubrication system isactuated by an impeller type oil pump contained within the accessoryhousing.

Induction System - These engines are equipped with either of twoMarvel-Schebler carburetors, MA-3A or MA-3SPA. See Table 1 formodel application. Both carburetors are of the single barrel float typeand are equipped with manual mixture control and "idle cut-off". Par-ticularly good distribution of the fuel-air mixture to each cylinder is ob-tained from the center zone induction system, which is integral with thesump and is submerged in oil, insuring a more uniform vaporization offuel and aiding in cooling the oil in the sump. From the riser the fuel-airmixture is distributed to each cylinder by individual intake pipes.

Ignition System - Dual ignition is furnished by two magnetos. ConsultTable 1 for proper model application. Depending on installation the igni-tion wiring is so arranged as shown in either figure 5-1, 5-2 or 5-3.


TABLE 1

MODEL APPLICATION

Model

0-235-C0-235-C,-E1,

-F1,-G10-235-C1B,-E1B,

-F1B,-G1B0-235-C2A,-E2A,-F2A,

-G2A,-K2A,-J2A0-235-L2A*,-N2A*,-P2A*

0-235-M1*

0-235-C2B,-E2B,-F2B,-G2B,-K2B,-J2B

0-235-C2C,-H2C0-235-K2C

0-235-L2C, -N2C**

0-290-D0-290-D20-290-D2A0-290-D2B0-290-D2C

Magneto

Left Right

S4LN-21 S4LN-20

S4LN-21 S4LN-20

S4LN-200 S4LN-204

S4LN-21 S4LN-20S4LN-21 S4LN-20

orS4LN-204

S4LN-21 S4LN-20or

S4LN-204

PropellerCarburetor Flange

Specification(Modified)

MA-3A or -3PA AS-127-2



MA-3A or -3PA AS-127-1MA-3A or -3PA AS-127-1

S4LN-122742514252

4252or

4281

S4LN-21S4LN-21S4LN-21S4LN-21S4LN-200

S4LN-120942504250or

4252

4250or

4281

S4LN-20S4LN-20S4LN-20S4LN-20S4LN-204

MA3A-3PA

MA-3A or -3PAMA-3A or -3PAMA-3A or -3PA

MA3A or -3PA

MA-3SPAMA-3SPAMA-3SPAMA-3SPAMA-3SPA

AS-127-2

AS-127-1AS-127-1AS-127-1

AS-127-1

AS-127-2AS-127-2AS-127-2AS-127-2AS-127-2

* 0-235-L2A, -M1, -N2A, -P2A may have two (2) S4LN-21 magnetos asoptional equipment.

** 0-235-L2C, -N2C may have two (2) 4252 magnetos as optional equipment.

1-4


SPECIFICATIONS

Page

Specifications -0-235 ................................... 2-1Specifications - 0-290 ................................... 2-2Accessory Drives ...................................... 2-2Alternate Power Ratings ..... .......................... 2-3Detail Weights ........................................ 2-4



SPECIFICATIONS0-235 SERIES

*-C-E -C1C -F-G-J -N-P

FAA Type Certificate 223 223Take-off horsepower 115 115Take-off RPM 2800 2800Rated horsepower 115 108Rated RPM 2800 2600Bore, inches 4.375 4.375Stroke, inches 3.875 3.875Displacement, cu. in. 233.3 233.3Compression ratio 6.50:1 6.75:1Prop. drive ratio 1:1 1:1Prop. driven rotation

(viewed from rear) Clockwise ClockwiseFiring orders 1-3-2-4 1-3-2-4Spark occurs, BTC 25 25Rocker clearance, cold .007/.009 .007/.009* - 0-235-C1 has provision for two position prop.

223125

2800125

28004.3753.875233.39.7:1

1:1

223116

2800116

25504.3753.875233.38.1:1

1:1

Clockwise Clockwise1-3-2-4 1-3-2-4

25 20.007/.009 .007/.009control valve.

FAA Type CertificateTake-off horsepowerTake-off RPMRated horsepowerRated RPMBore, inchesStroke, inchesDisplacement, cu. in.Compression ratioProp. drive ratioProp. drive rotation

(viewed from rear)Firing ordersSpark occurs, BTCRocker clearance.

cold

-K-L-M223118

2800118

28004.3753.875233.38.5:1

1:1

Clockwise1-3-2-4

20

-H -K2C

223115

2800108

26004.3753.875233.3

6.75:11:1

Clockwise1-3-2-4

25

223118

2800115

27004.3753.875233.38.5:1

1:1

Clockwise1-3-2-4

20

.007/.009 .007/.009 .007/.009NOTE

Engine models are categorized according to their basic series. Anymodel that varies in specification within a series is listed separately.

Spark advance is also found on name plate.

2-1

LYCOMING OPERATOR'S MANUAL0-235 AND 0-290 SERIES SECTION 2

SPECIFICATIONS

0-290 SERIES

-D2,-D2A

-D2B,-D2C

FAA Type CertificateTake-off horsepowerTake-off RPMRated horsepowerRated RPMBore, inchesStroke, inchesDisplacement, cubic in.Compression ratioPropeller drive ratioPropeller driven rotation

(viewed from rear)Firing orderSpark occurs, BTCValve rocker clearance

(hyd. tappets collapsed)Valve rocker clearance

(cold)

Accessory Drive

StarterGeneratorGenerator (Optional)AlternatorVacuum PumpHydraulic PumpTachometerMagnetoFuel PumpProp. GovernorAN Drive

* - Facing Drive Pad.

229130

2800125

26004.8753.875289.06.50:1

1:1

Clockwise1-3-2-4

25

229140

2800135

26004.8753.875289.0

7.50:11:1

Clockwise1-3-2-4

18

229140

2800135

26004.8753.875289.0

7.00:11:1

Clockwise1-3-2-4

25

.028-.080 .028-.080

.007/.009

Drive Ratio *Direction of Rotation

13.556:11.910:12.500:13.250:11.300:11.300:10.500:11.000:10.500:10.866:11.000:1

Counter-ClockwiseClockwiseClockwiseClockwise

Counter-ClockwiseCounter-Clockwise

ClockwiseClockwise

Plunger OperatedClockwise

Counter-Clockwise

2-2



ALTERNATE POWER RATINGS0-235 SERIES

0-235-C2C ..................................... 100 hp/2400 rpm

0-235-H2C ......................... ......... 100 hp/2400 rpm

0-235-L Series ................................ 105 hp/2400 rpm110 hp/2550 rpm112 hp/2600 rpm115 hp/2700 rpm

0-235-M Series ........................... 105 hp/2400 rpm110 hp/2550 rpm112 hp/2600 rpm115 hp/2700 rpm

0-235-N Series ........................... 103 hp/2400 rpm108 hp/2550 rpm110 hp/2600 rpm113 hp/2700 rpm

0-235-P Series ................................. 103 hp/2400 rpm110 hp/2600 rpm113 hp/2700 rpm

2-3



DETAIL WEIGHTS

1. STANDARD ENGINE (Average)

MODEL

0-235-C. ......... ... .. ... .... ... 240.00 lbs.0-235-C1B... .... ....................... ... 241.00 lbs.0-235-C1, -C2A ... ............... ...... . 242.00 lbs.0-235-C1C, -C2B, -H2C ... .......... ... 243.00 lbs.O-235-C2C .. ................. ......... ..... 244.00 lbs.O-235-K2C, -L2C .... ............................ 248.00 Lbs.O-235-E B, -F1B, -N2C ..... .................. .. 249.00 lbs.O-235-E2A, -F2A ....... ...... ......... ...... 250.00 lbs.O-235-F2B . . ..... ..... ...... ........... 251.00 lbs.O-235-K2A, -L2A .. ..................... .... 252.00 lbs.O-235-N2A. ..................... 252.00 lbs.0-235-G1, -G2A, -J2A, -K2B. ........................ 253.00 lbs.0-235-M1, -P2A .................. ..... 255.00 lbs.0-290-D ........................... ...... ...... 260.00 lbs.O-290-D2A, -D2C .............................. .. 264.00 lbs.0-290-D2B ............. ......... ..... 265.00 lbs.

2-4



Page

General ...................... ......................... 3-1Prestarting Items of Maintenance ........................ 3-2Starting Procedure .................... .................. 3-2Cold W eather Starting .................................. 3-3Ground Running and Warm-Up ........................... 3-3Checks Before Take-Off ................................. 3-3Operation in Flight ..................................... 3-4Use of Carburetor Heat Control .......................... 3-6Engine Flight Chart .................... ................. 3-8Operating Conditions .................................. 3-8Shut-Down Procedure ................................ 3-10APerformance Curves ............................ .. 3-11


SECTION 3


1. GENERAL. Close adherence to these instructions will greatly con-tribute to long life, economy and satisfactory operation of the engine.

NOTE

YOUR ATTENTION IS DIRECTED IN PARTICULAR TO THEWARRANTIES THAT APPEAR IN THE FRONT OF THISMANUAL REGARDING ENGINE SPEED, THE USE OFSPECIFIED FUELS AND LUBRICANTS, REPAIRS ANDALTERATIONS. PERHAPS NO OTHER ITEM OF ENGINEOPERATION AND MAINTENANCE CONTRIBUTES QUITE SOMUCH TO SATISFACTORY PERFORMANCE AND LONGLIFE ASTHE CONSTANT USE OF CORRECT GRADES OF FUEL AND OILCORRECT ENGINE TIMING, AND FLYING THE AIRPLANE ATALL TIMES WITHIN THE SPEED AND POWER RANGESPECIFIED FOR THE ENGINE. DO NOT FORGET THAT VIOLA-TION OF THE OPERATION AND MAINTENANCE SPECIFICA-TIONS FOR YOUR ENGINE WILL NOT ONLY VOID YOUR WAR-RANTY BUT WILL SHORTEN THE LIFE OF YOUR ENGINEAFTER ITS WARRANTY PERIOD HAS PASSED.

New engines have been carefully run-in by Lycoming andtherefore no further break-in is necessary insofar as operation is concern-ed; however, new or newly overhauled engines should be operated usingonly the lubricating oils recommended in the latest edition of Service In-struction No. 1014.

NOTE

Cruising should be done at 65% to 75% power until a total of 50 hours hasaccumulated or oil consumption has stabilized. This is to insure properseating of the rings and is applicable to new engines, and engines in ser-vice following cylinder replacement or top overhaul at one of morecylinders.

The minimum fuel octane rating is listed in the Flight Chart, Part 8 ofthis section. Under no circumstances should fuel of a lower octane ratingor automotive (regardless of octane rating) be used.

3-1



2. PRESTARTING ITEMS OF MAINTENANCE. Before starting theaircraft engine for the first flight of the day, there are several items ofmaintenance inspection that should be performed. These are described inSection 4 under Daily Pre-Flight Inspection. They must be observedbefore the engine is started.

3. STARTING PROCEDURE.

a. Perform pre-flight inspection.

b. Head airplane into wind.

c. Lock wheels by either wheel brakes or chocks.

d. Set carburetor heat control in "cold" position.

e. Set propeller governor (if applicable) in "Full RPM" position.

f. Turn fuel valve to "on" position.

g. Set throttle at 1/4 travel.

h. Move mixture control to "Full Rich".

i. Turn boost pump on.

j. Pump throttle to full open and back to idle position for 2 to 3 strokesfor a cold engine. If engine is equipped with a priming system, coldengine may be primed with 1 to 3 strokes of the priming pump.

k. Set magneto selector switch. Consult airframe manufacturer'shandbook for correct position.

1. Engage starter.

m. When engine fires, place magneto switch in "Both" position.

n. Check oil pressure gage. If oil pressure is not indicated within thirtyseconds, stop engine and determine trouble.

3-2



4. COLD WEATHER STARTING. During extreme cold weather, it maybe necessary to preheat the engine and oil before starting.

5. GROUND RUNNING AND WARM-UP. Subject engines are airpressure cooled and depend on the forward movement of the aircraft tomaintain proper cooling. Particular care is necessary, therefore, whenoperating these engines on the ground. To prevent overheating, it isrecommended that the following procedures be observed.

NOTE

Any ground check that requires full throttle operation must be limited tothree minutes, or less if the indicated cylinder head temperature exceedsthe maximum as stated in this manual

a. Head the aircraft into the wind.

b. If a controllable pitch propeller is installed, operated the engine onthe ground only with the propeller in minimum blade angle setting.

c. Leave the mixture control in "Full Rich".

d. Avoid prolonged idling at low RPM as this practice may result infouled plugs. Limit ground running to minimum time necessary towarm engine for take-off.

e. Use of the carburetor air heat on the ground must be held to an ab-solute minimum. On some installations the air does not pass throughthe air filter and dirt and foreign substances can be taken into theengine with the resultant cylinder and piston ring wear. Carburetor airheat should be used on the ground only to make certain it is function-ing properly.

6. CHECKS BEFORE TAKE-OFF.

a. Warm up as directed above.

b. Check both oil temperature and oil pressure.

c. Set carburetor air heat control for "full heat" to check operation.Loss of manifold pressure or RPM (or both), depending on whether afixed pitch or controllable pitch propeller is installed on the aircraft,will result if the control is working properly. Return control to "cold"position after check.

3-3



d. A proper magneto check is important. Additional factors, other thenthe ignition system, affect magneto drop-off. They are, load-poweroutput, propeller pitch and mixture strength. The important thing isthat the engine runs smoothly because drop-off is affected by thevariables listed above. Make the magneto check in accordance with thefollowing procedures:

(1) Controllable Pitch Propeller - With propeller in minimum pitchangle, set the engine to produce 50 to 65% power as indicated by themanifold pressure gage. Mixture control should be in the full richposition. At these settings the ignition system and spark plugs mustwork harder because of the greater pressure within the cylinders.Under these conditions, ignition problems, if they exist, will occur.Magneto checks at low power settings will only indicate fuel-airdistribution quality.

NOTE

Aircraft that are equipped with fixd pitch propellers, or not equippedwith manifold pressure gage, may check magneto drop-off with engineoperating at approximately 1800 RPM (2000 RPM maximum).

(2) Switch from both magnetos to one and note drop-off, return toboth until engine regains speed and switch to the other magneto andnote drop-off, then return to both. Drop-off should not exceed 175and should not exceed 50 RPM difference between magnetos. Asmooth drop-off past normal is usually a sign of a too lean or too richmixture.

(3) Do not operate on a single magneto for too long a period, 2 to 3seconds is usually sufficient to check drop-off and will minimize plugfouling.

7. OPERATION IN FLIGHT.

A. See airframe manufacturer's instructions for correct manifoldpressure for power settings.

B. Fuel Mixture Leaning Procedure - Improper fuel-air mixture duringflight is responsible for many engine problems, particularly duringtake-off and climb power settings. The procedures described in thismanual provide proper fuel-air mixture when leaning Avco Lycomingengines, they have proven to be both economical and practical byeliminating excessive fuel consumption and reducing damaged partsreplacement. It is therefore recommended that operators of all Avco



Lycoming aircraft powerplants utilize the instructions in this publica-tion any time the fuel-air mixture is adjusted during flight.

LEANING PRECAUTIONS

Never exceed the maximum red line cylinder head temperature limit.

For continuous operation cylinder head temperatures should be main-tained below 435°F. (224°C.).

On direct drive engines with manual mixture control maintain mixturecontrol in "Full Rich" position for rated take-off rated maxmimum con-tinuous, climb and cruise powers above 75%. However, during take-offfrom high elevation airport or during climb, roughness or loss of powermay result from over-richness. In such a case adjust mixture control onlyenough to obtain smooth operation - not for economy. Observe in-struments for temperature rise. Rough operation due to over-rich fuel-airmixture is most likely to be encountered at altitude above 5,000 feet.

Always enrich mixture before increasing power.

C. LEANING TO EXHAUST GAS TEMPERATURE GAGE.

(1) Above 75% power -Never lean beyond 150°F. on rich side of peakEGT unless aircraft operator's manual shows otherwise. Monitorcylinder head temperature.

(2) 75% power and below - Operate at peak EGT.

D. LEANING WITH MANUAL MIXTURE CONTROL. (At 75%power or less without flowmeter or EGT gage.)

(1) Slowly move mixture control from "Full Rich" position towardlean position.

(2) Continue leaning until engine roughness is noted.

(3) Enrich until engine runs smoothly and power is regained.

E. ALTERNATE METHOD. (In calm air and engines with fixed pitchpropellers.)

(1) Slowly move mixture control toward lean position while closelywatching tachometer. Continue leaning until RPM decreases.

(2) At this point enrich until RPM just peaks. Correct fuel-air ratiois obtained at this point.

3-5



NOTE

Leaning may be done at any altitude that the engine will accept leaning:The greater the altitude the more important leaning becomes. Properleaning is important because more engine power and increased air speedare obtained along with decreased fuel consumption, longer spark pluglife, less lead fouling, and more normal oil and cylinder headtemperatures. Engine damage from leaning the mixture does not occurat the specified cruise power for the model engine in a basically healthypower plant, but is the result of improper leaning atpower settings aboverecommended cruise.

F. Use of Carburetor Heat Control - Under certain moist atmosphericconditions, it is possible for ice to form in the induction system even insummer weather. This is due to the high air velocity through the car-buretor venturi and the absorption of heat from this air byevaporization of the fuel. The temperature in the mixture chambermay drop 20°F. to 70°F. below the temperature of the incoming air. Ifthis air contains a large amount of moisture, the cooling process willcause precipitation in the form of ice. These ice formations generallybegin in the vicinity of the butterfly and will often build up to such anextent that a drop in manifold power output results. This loss of poweris reflected by a drop in manifold pressure in installations equippedwith constant speed propellers and a drop in manifold pressure andRPM in installations equipped with fixed pitch propellers. If notdetected, this condition will continue to such an extent that thereduced power will cause complete engine stoppage.

To avoid this condition, all installations are equipped with a systemfor preheating the incoming air supply to the carburetor. In this way,sufficient heat is added to replace the heat loss to vaporization of fuel,and the mixing chamber's temperature cannot drop to the freezingpoint of water. This air preheater is essentially a tube or jacketthrough which the exhaust pipe from one or more cylinders is passed,and the air flowing over these surfaces is raised to the requiredtemperature before entering the carburetor. Consistently hightemperatures are to be avoided because of a loss of power and adecided variation of the mixture. High charge temperatures also favordetonation and preignition, both of which are to be avoided if normalservice life is to be expected from the engine. The following outline isthe proper method of utilizing the carburetor heat control.



(1) Take-Off- Take-off should be made with carburetor heat in fullcold position. The possibility of icing at wide throttle opening is veryremote.

(2) Flight Operation - The carburetor air heat control should be left inthe cold position during normal flight operations. On damp, cloudy,foggy or hazy days, regardless of outside temperature, keep a sharplookout for loss of power. This loss of power will be shown by unac-countable loss in manifold pressure or RPM or both, depending onwhether a constant speed or fixed pitch propeller is installed on theaircraft. When this situation arises, apply full carburetor air heatand open the throttle to limiting manifold pressure. This will resultin a slight additional drop in manifold pressure which is normal andthis drop will be regained as the ice is melted out of the inductionsystem. When the ice has been melted from the induction system,the carburetor heat control should be returned to the cold position.In those aircraft equipped with a carburetor air temperature gage,partial heat may be used to keep the mixture temperature above thefreezing point (32°F.).

WARNING

Caution must be exercised when operating with partial heat on aircraftthat do not have a carburetor air temperature gage. Moisture in crystalform that would ordinarily pass through the induction system, can beraised in temperature by use of partial heat to the point where thecrystals are melted into liquid form. This moisture can form carburetorice due to the temperature drop as it passes through the venturi of thecarburetor. It is advisable, therefore, to use either full heat or no heat inaircraft that are not equipped with a carburetor air temperature gage.

(3) Landing Approach - In making an approach for a landing, car-buretor air heat should usually be in the "Full Cold" position.However, if icing conditions are known or suspected, then "FullHeat" should be applied. In the case that full power need be appliedunder these conditions, as for an aborted landing, the carburetorheat should be returned to "Full Cold" prior to power application.See aircraft flight manual for specific instructions.

3-7



8. ENGINE FLIGHT CHART.

Fuel and Oil

Model *Aviation Grade Fuel

O-235-C, -E, -H2C .. . . . ................ . 80/87 octane minimumO-235-F, -G, -J, -K, -L, -M, -N, -P .... . 100/100LL octane minimumO-290-D, -D2 .... . . . . . ..... . .. 80/87 octane minimum

* Refer to the latest edition of Service Instruction No. 1070.

NOTE

Aviation grade 100LL fuels in which the lead content is limited to 2 c.c. per gallonare approved for continuous use in the above listed engines.

**Recommended Grade OilMIL-L-22851

Average MIL-L-6082 Ashless DispersantAmbient Air Grades Grades

All Temperatures ....-- SAE 15W50 or 20W50Above 80°F. (26.6°C.) SAE 60 SAE 60Above 60°F. (15.5°C.) SAE 50 SAE 40 or SAE 5030 (-1.11°C.) to 90°F. (32.2°C.) SAE 40 SAE 400° (-17.8°C.) to 70°F. (21.1°C.) SAE 30 SAE 40, 30 or 20W40

Below 10°F. (-12.2 C.) SAE 20 SAE 30 or 20W30

** Refer to the latest edition of Service Instruction No. 1014.

0-290-D,0-235 Series -D2 Series

Oil Sump Capacity 6 Qts. 8 Qts.Minimum Safe Quantity

of Oil in Sump 2 Qts. 2 Qts.

It is recommended that the lubricating oil be changed every 50 flying hours (orevery 25 hours, if engine does not have a full-flow oil filter).

OPERATING CONDITIONS

Oil Pressure, psi Maximum Minimum Idling

0-235 Series-C, -E, -F, -G, -H2C, -J, -K, -M 90 60 25-B, -L*, -N 90 60 15-P 90 55 15

* Front of engine 90 50 15

SECTION 3

All 0-235 series, except

-L, -N, -P

0-290 Series-D-D2

-D2

Fuel pressure (psi)

All 0-235 models, O-290-D20-290-D

Average AmbienTemperature

Above 60°F. (15.5°C.)30 (-1.11°C.) to 90°F.0° (-17.8°C.) to 70°F.

Below 10°F. (-12.2°C.)

Engine oil temperatuoperation.


0-235 AND 0-290 SERIES

OPERATING CONDITIONS (Cont.)

START/WARM-UP

100

115

Maximum Minimum Idling85 60 2590 60 25

START/WARM-UP

100

Maximum Desired Minimum

290-D2

t Air

(32.2°C.)(21.1°C.)

55

33

0.50.5

Oil Inlet Temperature

Desired Maximum

180°F. (82°C.) 245°F. (118°C.)180°F. (82°C.) 245"F. (118°C.)170°F. (77°C.) 245 F. (118"C.)160°F. (71°C.) 245°F. (118 C.)

not be below 140"F. (60"C.) during continuous

3-8A



OPERATING CONDITIONS (CONT.)

FuelCons.

Operation RPM HP Gal./Hr.

0-235-C, -E

Normal Rated 2800 115 10.7Performance Cruise

(75% Rated) 2350 86 7.3Economy Cruise

(65% Rated) 2250 75 5.8

0-235-F, -G, -J

Normal Rated 2800 125 10.7Performance Cruise


(65% Rated) 2400 81 5.8

0-290-D Series

Take-Off 2800 130Normal Rated 2600 125 11.9Performance Cruise


(65% Rated) 2250 81 6.5

0-290-D2 Series

Take-Off 2800 140Normal Rated 2600 135 12.6Performance Cruise


(65% Rated) 2200 87 6.3

Max. *Max.Oil Cons. Cyl. HeadQts./Hr. Temp.

0.52

0.29

0.25

0.56

0.31

0.27

0.56

0.31

0.27

0.60

0.34

0.29

500°F. (2600 C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

* - At Bayonet Location - For maximum service life of the engine, maintaincylinder head temperatures between 150°F. (65°C.) and 400°F. (204°C.) dur-ing continuous operation.

3-9

SECTION 3



OPERATING CONDITIONS (CONT.)

Operation

FuelCons.

RPM HP Gal./Hr.

0-235-K, -L, -M

Max. Max.Oil Cons. Cyl. HeadQts./Hr. Temp.

Normal Rated 2800Performance Cruise

(75% Rated) 2500Economy Cruise

(65% Rated) 2400

Take-off 2800Normal Rated 2700Performance Cruise


(65% Rated) 2300


('75% Rated) 2350Economy Cruise

(65% Rated) 2250



65% Rated) 2200

118 9.5

89 6.7

77 5.8

0-235-K2C

118115 9.2

86 6.4

75 5.6

0-235-H Series

115 --108 10.7

81 7.3

70 5.8

0-235-N, -P

116108 9.2

81 6.2

70 5.3

.39 500°F. (260°C.)

.30 500°F. (260°C.)

.27 500°F. (260°C.)

.38

.29

.25

.36

.27

.23

.36

.27

.23

500°F. (260°C.)500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)

500°F. (260°C.)500°F. (260°C)

500°F. (260°C.)

500°F. (260°C.)

3-10



.9 SHUT-DOWN PRO('EDURE.

a. Idle engine at approximately 800 to 900 RPM until there is adecided drop in cylinder head temperature.

b. Move mixture control to "Idle Cut-Off".

c. After engine stops, set magneto switch at the "off" position; thiswill prevent after-firing.

Revised March. 1982 3-10A

LYCOMING OPERATOR’S MANUAL


CURVE NO. 8210

hRxNRE SETTING

Figure 3-l. Power and Fuel Consumption Curve o-235-c

3-11

Figure 3-2. Sea Level and Altitude Performanc e - 0-235-C1, -El, -H2 Series



Figure 3-3. Fuel Flow vs Percent Rated Power. 0-235-C1, -El, -H2 Series

3-13

Figure 3-4. Sea Level and Altitude Performance. 0-290-D



CURVE NO. 8583-A .2-=---J- --

Figure 3-5. Power and Fuel Consumption Curve- 0-290-D

3-15



Figure 3.7. Power and Fuel Consumption Curve- 0-290-D2, -D2A

3-17



USING CURVE TO FIND ACTUAL HORSEPOWER -

The following is an example of how to use the Sea Level and AltitudePerformance curves, printed on these pages, to determine actualhorsepower being delivered by the engine for given altitude, RPM,manifold pressure and air inlet temperature. This example (using figuresfrom curve on opposite page) is for illustration purposes only.

1. Determine equivalent full throttle horsepower on altitude perfor-mance curve for observed manifold pressure and RPM (Example - At2400 RPM and 23.8 in. Hg., locate Point "A").

2. Repeat above procedure on sea level performance curve (Example-Point "B").

3. Transfer value obtained in Step 2 to the altitude performance curve(Example - Point "C").

4. Connect point "A" and point "C" with a straight line.

5. Read horsepower on line "CA" for given altitude (Example - At 1800feet with a power setting of 2400 RPM and 23.8 in. Hg., horsepower is99.5, Point "D").

6. Correct power approximately 1% for each 10°F. variation in intakeair temperature from the standard altitude temperature shown below.Add corrections for temperatures below standard, subtract fortemperatures above standard. (Example - With an air inlettemperature of 22°F. at an altitude of 1800 feet, 52°F. - 22"F. = 30°F.variation. 1% for each 10° variation is 3%. 3% of 99.5 horsepower isapproximately 3 horsepower. Since temperature is below standard,add correction: 99.5 + 3 = 102.5 horsepower, Point "E").

STANDARD ALTITUDE TEMPERATURES IN DEGREES F.

Pressure Altitude(Thousands) SL 2 4 6 8 10 12 14 16 18 20 22 24

Standard Altitude(Temperature °F.) 59 52 45 38 31 23 16 9 + 2 -5 -12 -19 -27

3-19


SECTION 3 o-235 AND 0.290 SERIES

Figure 3-9. Power and Fuel Consumption Curve . 0-290-D2B,-D2C

3-20


o-235 AND O-290 SERIES SECTION 3

Figure 3-10. Fuel Flow vs Percent Rated Power - 0-235-F. -G Series

3-21

9

I



FUEL FLOW VS. PERCENT RATED POWERAVCO LYCOMING 0-235-K, -L, -M SERIESCOMPRESSION RATIO 8 50 1SPARK ADVANCE 20

°BTC

CARBURETOR. MARVEL SCHEBLER MA-3A or MA-3PAFUEL GRADE. MINIMUM 100/1OOLL

PERCENT RATED POWER

Figure 3-12. Fuel Flow vs Percent Rated Power -0-235-K, -L, -M Series

3-23

LY

CO

MIN

G O

PE

RA

TO

R'S

MA

NU

AL

SEC

TIO

N 3

0-235 AN

D 0-290 SE

RIE

S

Figure 3-13. Sea Level and A

ltitude Performance -0-235-K

, -L, -M

Series

3-24


FUEL FLOW vs. HORSEPOWERLYCOMING 0-235-N, -P SERIES

CURVE NO. 13401

10

MINIMUM-ALLOWABLE FUEL FLOW

0 I

9

8

7

5

060 70 80 90 100 110

BRAKE HORSEPOWER

Figure 3-14. Fuel Flow vs. Horsepower0-235-N, -P Series

120

3-25

z

LYC

OM

ING

OP

ER

AT

OR

'S M

AN

UA

L

0-235 AN

D 0-290 SE

RIE

SSE

CT

ION

3

z

--

Figure 3-15. Sea Level and A

ltitude Perform

ance0-235-N

, -P Series

3-26


PERIODIC INSPECTIONS

Page

Pre-Starting Inspection ................................. 4-1Daily Pre-Flight ................................ ..... 4-225-Hour Inspection ..................................... 4-250-Hour Inspection ..................................... 4-2100-Hour Inspection .................................... 4-4400-Hour Inspection ..... ............................... 4-5Non-Scheduled Inspection ............................... 4-5



SECTION 4

PERIODIC INSPECTION

NOTE

Perhaps no other factor is quite so important to safety and durability ofthe aircraft and its components as faithful and diligent attention toregular checks for minor troubles and prompt repair when they arefound.

The operator should bear in mind that the items listed in the followingpages do not constitute a complete aircraft inspection, but are meant forthe engine only. Consult the airframe manufacturer's handbook for addi-tion instructions.

Pre-Starting Inspection -The daily pre-flight inspection is a check of theaircraft prior to the first flight of the day. This inspection is to determinethe general condition of the aircraft and engine.

The importance of proper pre-flight inspection cannot be over em-phasize. Statistics prove several hundred accidents occur yearly directlyresponsible to poor pre-flight.

Among the major causes of poor pre-flight inspection are lack of con-centration, reluctance to acknowledge the need for a check list,carelessness bred by familiarity and haste.

4-1



1. DAILY PRE-FLIGHT.

a. Be sure all switches are in the "Off" position.

b. Be sure magneto ground wires are connected.c. Check oil level.d. See that fuel tanks are full.

e. Check fuel and oil line connections, note minor indications for repairat 50 hour inspection. Repair any major leaks before aircraft is flown.

f. Open the fuel drain to remove any accumulation of water and sedi-ment.

g. Make sure all shields and cowling are in place and secure. If any aremissing or damaged, repair or replacement should be made before theaircraft is flown.

h. Check controls for general condition, travel and freedom of opera-tion.

i. Induction system air filter should be inspected and serviced in ac-cordance with the airframe manufacturer's recommendations.

2. 25-HOUR INSPECTION. After the first twenty-five hours operatingtime, new, remanufactured or newly overhauled engines should undergoa 50 hour inspection including draining and renewing lubricating oil.

3. 50-HOUR INSPECTION. In addition to the items listed for daily pre-flight inspection, the following maintenance checks should be made afterevery 50 hours of operation.

a. Ignition System - Remove spark plugs; test, clean and regap.Replace if necessary.

Examine spark plug leads of cable and ceramics for corrosion anddeposits. This condition is evidence of either leaking spark plugs, im-proper cleaning of the spark plug walls or connector ends. Where thiscondition is found, clean the cable ends, spark plug walls and ceramicswith a dry, clean cloth or a clean cloth moistened with methyl-ethylketone. All parts should be clean and dry before reassembly.

Check ignition harness for security of mounting clamps and be sureconnections are tight at spark plug and magneto terminals.

4-2



b. Fuel and Induction System - Check primer lines for leaks andsecurity of clamps. Drain carburetor and clean carburetor fuelstrainer. Check mixture control and throttle linkage for travel,freedom of movement, security of clamps and lubricate if necessaryCheck carburetor air intake ducts for leaks, security, filter damage;evidence of dust or other solid material in the ducts is indicative ofinadequate filter care or damaged filter. Check vent lines for evidenceof filter or oil seepage; if present, fuel pump may require replacement.

c. Lubrication System - Check oil lines for leaks, particularly at con-nections; for security of anchorage and for wear due to rubbing orvibration, for dents and cracks.

Drain and refill sump with new oil on installation not employingreplaceable external oil filter. See the latest revision to Service In-struction No. 1014 for recommended lubricating oils. Seasonal gradesare listed in Section 3, Paragraph 8 of this manual.

Remove oil suction and oil pressure screens and clean thoroughly.Note carefully for presence of metal particles that are indicative ofinternal engine damage.

If engine is equipped with external oil filters, replace at this time.Before disposing of filter, check interior for traces of metal particlesthat might be evidence of internal engine damage.

d. Exhaust System - Check attaching flanges at exhaust ports oncylinders for evidence of leakage. If they are loose, they must beremoved and machined flat before they are reassembled and tightened.Examine exhaust manifolds for general condition.

e. Cooling System - Check cowling for damage and secure anchorage.Any damaged or missing part of the cooling system must be repairedor replaced before the aircraft resumes operation.

f. Cylinders - Check rocker box covers for evidence of oil leaks. Iffound, replace gasket and tighten screws to specified torque (50 inchpounds).

Check cylinders for evidence of excessive heat which is indicated byburned paint on the cylinder. This condition is indicative of internaldamage to the cylinder and, if found, its cause must be determined andcorrected before the aircraft resumes operation.

4-3



Heavy discoloration and appearance of seepage at the cylinder headand barrel attachment area is usually due to emission of thread lubri-cant used during assembly of the barrel at the factory, or by slight gasleakage which stops after cylinder has been in service for awhile. Thiscondition is neither harmful nor detrimental to the engine performanceand operation. If it can be proven that the leakage exceeds these con-ditions, the cylinder should be replaced.

4. 100-HOUR INSPECTION. In addition to the items listed for dailypre-flight and 50 hour inspection the following maintenance checksshouldbe made after every one hundred hours of operation.

a. Electrical System - Check all wiring connected to the engine or ac-cessories. Any shielded cables that are damaged should be replaced.Replace faulty clamps or loose wires and check terminals for securityand cleanliness.

b. Magnetos - Check condition of breakers points. Check for excessiveoil in the breaker compartment, if found, wipe dry with a clean lintlesscloth. The felt located at the breaker points should be lubricated inaccordance with the magneto manufacturer's instructions. Checkmagneto to engine timing. Timing procedure is described in Section 5,Paragraph lb of this manual.

c. Engine Accessories - Engine mounted accessories such as pumps,temperature and pressure sensing units should be checked for securemounting, tight connections and terminals.

d Cylinders - Check visually for cracked or broken fins.

e. Engine Mounts - Check engine mounting bolts and bushings forsecurity and excessive wear. Replace any bushings that are excessive-ly worn.

f Primer Nozzles - Disconnect primer nozzles from engine and checkfor equal flow.

g. Valve Rockers (0-235 and 0-290-D) - Check clearance. See Page 5-15,Paragraph 11 for valve rocker clearance.

h. Carburetor - Check throttle body attaching screws for tightness.The correct torque for these screws is 40 to 50 inch pounds.

4-4



i. Lubrication System - Drain and renew lubrication oil. Replace oilfilter.

5. 400-HOUR INSPECTION. In addition to the items listed for dailypre-flight, 50 hour and 100 hour inspections, the following maintenancecheck should be made after every 400 hours of operation.

Valve Inspection - Remove rocker box covers and check for freedom ofvalve rockers when valves are closed. Look for evidence of abnormalwear or broken parts in the area of the valve tips, valve keeper, springsand spring seat. If any indications are found, the cylinder and all of itscomponents should be removed (including the piston and connecting rodassembly) and inspected for further damage. Replace any parts that donot conform with limits shown in the latest publication of Special Ser-vice Publication No. SSP1776.

6. NON-SCHEDULED INSPECTIONS. Occasionally, service bulletinsor service instructions are issued by Avco Lycoming Division that re-quire inspection procedures that are not listed in this manual. Suchpublications, usually are limited to specified engine models and becomeobsolete after corrective modification has been accomplished. All suchpublications are available from Avco ,ycoming distributors, or from thefactory by subscription. Consult Service Letter No. L114 for subscrip-tion information. Maintenance facilities should have an up-to-date file ofthese publications available at all times.

4-5



Page

Ignition and Electrical System

Harness and Wire Replacement ......................... 5-1Timing Magnetos to Engine ............................ 5-1Generator or Alternator Output ......................... 5-6

Fuel System

Repair of Fuel Leaks .................................. 5-7Carburetor Inlet Screen Assembly ...................... 5-7Fuel Grades and Limitations ........................... 5-7Air Intake Ducts and Filters ......... .................. 5-7Idle Speed and Mixture Adjustment ..................... 5-7

Lubrication System

Oil Grades and Limitations ........................... 5-8Oil Sump Capacity .................................... 5-8Oil Suction and Oil Pressure Screens ..................... 5-8Oil Relief Valve .................... .................. 5-9

Cylinder Assembly

Removal of Cylinder Assembly ......................... 5-9Assembly of Cylinder Assembly ....................... 5-12

Generator Drive Belt Tension ........................... 5-14



SECTION 5


The procedures described in this section are provided to guide and in-struct personnel in performing such maintenance operations that may berequired in conjunction with the periodic inspections listed in thepreceding section. No attempt is made to include repair and replacementoperations that will be found in the applicable Avco Lycoming OverhaulManual.

1. IGNITION AND ELECTRICAL SYSTEM.

a. Ignition Harness and Wire Replacement - In the event that an ig-nition harness or an individual lead is to be replaced, consult the wir-ing diagram to be sure harness is correctly installed. Mark location ofclamps and clips to be certain the replacement is clamped at correctlocations.

b. Timing Magnetos to Engine - Although several combinations ofmagnetos are used on this series engines, (see Table of Models formodel application) the timing procedures, in the following paragraphs,are the same for all magnetos.

NOTE

Either the impulse coupling or retard breaker magneto (whichever is ap-plicable) is installed on the left side of the engine.

(1) Remove a spark plug from No. 1 cylinder and place a thumb overthe spark plug hole. Rotate the crankshaft in direction of normalrotation until the compression stroke is reached, this is indicated bya positive pressure inside the cylinder tending to push the thumb offthe spark plug hole. Continue rotating the crankshaft in direction ofnormal rotation until the advance timing mark on the front face ofthe starter ring gear is in exact alignment with the small hole locatedat the two o'clock position on the front face of the starter housing.Consult specification for correct timing mark for your installation.At this point, the engine is ready for assembly of the magnetos.

5-1


0-235 AND 0-290 SERIESSECTION 5

FIRING ORDER 1-3-2-4

Figure 5-1. Ignition Wiring Diagram

5-2




Figure 5-2. Ignition Wiring Diagram (Optional)

5-3


0-235 AND 0-290 SERIESSECTION 5


Figure 5-3. Ignition Wiring Diagram (Optional)

5-4



All timing procedures, except positioning the magneto in the numberone cylinder advance engine firing position, are the same for allmagnetos.

The method of positioning the Slick magnetos in the number onecylinder advance engine firing position is contained in the followingparagraphs. The method for Bendix magnetos may be found on page 5-6.

(Impulse Coupling Magneto) Hold the No. 1 lead wire spring 1/16 in. to1/8 in. away from the magneto frame and turn the impulse coupling oneclick at a time until a strong spark jumps between the spring and theframe. Hold the magneto firmly so the coupling will not move beyondthe point where it trips and the spark occurs. Reverse the rotation ap-proximately 25 until the timing pin hole appears in the center of thevent plug hole. Hold the rotor by inserting the timing pin, and line thetiming pin with the center of the vent plug hole.

(Conventional Magneto) Hold the No. 1 lead wire spring 1/8 in. awayfrom the frame. Turn the gear counter-clockwise vigorously through theflux lines until a strong spark occurs at the lead. Reverse the rotation in-to the flux until the timing pin hole appears in the center of the vent plughole and insert the timing pin into the hole.

5-5



NOTE

If the crankshaft is accidently turned in the direction opposite normalrotation, repeat the above procedure as accumulated backlash will makethe final timing incorrect.

(2) Remove the inspection plugs from both magnetos and turn thedrive shafts in direction of normal rotation until the first paintedchamfered tooth on the distributor gear is aligned in the center ofthe inspection window. Being sure that the gear does not move fromthis position, install gaskets and magnetos on the engine. Securewith washers and nuts; tighten only finger tight.

NOTE

In order to turn the shaft on an impulse coupling magneto, depress thepawl on the impulse coupling with the finger.

(3) Using a battery powered timing light, attach the positive lead toa suitable terminal connected to the ground terminal of the magnetoand the negative lead to any unpainted portion of the engine. Rotatethe magneto in its mounting flange to a point where the light comeson, then slowly turn it in the opposite direction until the light goesout. Bring the magneto back slowly until the light just comes on.Repeat this with the second magneto.

NOTE

Some timing lights operate in the reverse manner as described above, thelight comes on when the breaker points open. Check your timing light in-structions.

(4) After both magnetos have been timed, check, as described below,to ascertain that both magnetos are set to fire simutaneously.

(5) Back off the crankshaft a few degrees, the timing lights should goout. Bring the crankshaft slowly back in direction of normal rotationuntil the timing mark and the hole in the starter housing are inalignment. At this point, both lights should go on simultaneously.Tighten nuts to specified torque (150 inch pounds).

c. Generator or Alternator Output - The generator or alternator(whichever is applicable) should be checked to determine that thespecified voltage and current are being obtained.



2. FUEL SYSTEM.

a. Repair of Fuel Leaks - In the event a line or fitting in the fuel systemis replaced, only a fuel soluable lubricant, such as clean engine oil orLoctite Hydraulic Sealant, may be used on the threads. Any otherthread lubricant or compound must not be used.

b. Carburetor Inlet Screen Assembly - Remove and check the screen fordistortion or openings in the strainer. Replace for either of these con-ditions. Clean assembly in solvent and dry with compressed air. To in-stall the screen asembly, place the gasket on the assembly and installin the throttle body, then tighten to 35 - 40 inch pounds torque.

c. Fuel Grades and Limitations -The recommended aviation grade forsubject engines is listed in the Engine Flight Chart on page 3-8 of thismanual. In the event that the specified fuel is not available at somelocations, it is permissible to use higher octane fuel. Fuel of a loweroctane then specified is not to be used. Under no circumstances shouldautomotive fuel be used (regardless of octane rating).

NOTE

These engines are equipped with solid stem valves and should use higheroctane fuel only for limited operation. It is recommended that personnelbe familiar with Service Instruction No. 1070 regarding specified fuel forAvco Lycoming engines.

d Air Intake Ducts and Filter - Check all air intake ducts for dirt orrestrictions. Inspect and service air filters as instructed in the air-frame manufacturer's handbook.

e. Idle Speed and Mixture Adjustment -

(1) Start the engine and warm up in the usual manner until oil andcylinder head temperatures are normal.

(2) Check magnetos. If the "mag-drop" is normal, proceed with idleadjustment.

(3) Set throttle stop screw so that the engine idles at the airframemanufacturer's recommended idling RPM. If the RPM changesappreciably after making idle mixture adjustment during the suc-ceeding steps, readjust the idle speed.



(4) When the idling speed has been stabilized, move the cockpitmixture control lever with smooth, steady pull toward the "Idle Cut-Off" position and observe the tachometer for any change during theleaning process. Caution must be exercised to return the mixturecontrol to the "Full Rich" position before the RPM can drop to apoint where the engine cuts out. An increase of more than 50 RPMwhile "leaning" out indicates an excessively rich idle mixture. Animmediate decrease in RPM (if not preceded by a momentary in-crease) indicates the idle mixture is too lean.

If the above indicates that the idle adjustment is too rich or toolean, turn the idle mixture adjustment in the direction required forcorrection, and check this new position by repeating the aboveprocedure. Make additional adjustments as necessary until a checkresults in a momentary pick-up of approximately 50 RPM. Eachtime the adjustment is changed, the engine should be run up to 2000RPM to clear the engine before proceeding with the RPM check.Make the final adjustment of the idle speed adjustment to obtainthe desired idling RPM with closed throttle. The above method aimsat a setting that will obtain maximum RPM with minimum manifoldpressure. In case the setting does not remain stable, check the idlelinkage; any looseness in this linkage would cause erratic idling. Inall cases, allowance should be made for the effect of weather condi-tions and field altitude upon idling adjustment.

3. LUBRICATION SYSTEM.

a. Oil Grades and Limitations - Service the engine with grade recom-mended in Flight Chart, Section 3-8.

b. Oil Sump Capacity -

0-235 Series .................................. 6 U.S. Quarts0-290-D and -D2 Series .......................... 8 U.S. QuartsMinimum Safe Quantity in Sump ................. 2 U.S. Quarts

c. Oil Suction and Oil Pressure Screens. For engines without a full-flowoil filter, change oil and inspect and clean screens every 25 hours.

NOTE

On installations employing full-flow oil filters, step c. is not practical atthis time, but should be observed at the 100 hour inspection.

5-8



c. Oil Relief Valve - Subject engines are equipped with either an ad-justable or a non-adjustable oil relief valve located in the rightcrankcase half to the rear of no. 3 cylinder pad. The adjustable valvewill maintain the oil pressure within specified limits by screwing theadjusting screw inward to increase pressure and outward to decreasepressure. The non-adjustable valve can control pressure by the addi-tion of a maximum of nine STD-425 washers under the cap to increasepressure or a spacer (P/N 73629 or 73630) under the cap to decreasepressure.

d Oil Relief Valve (Adjustable) - The adjustable oil relief valve enablesthe operator to maintain engine oil pressure within the specified limits.If the pressure under normal operating conditions should consistentlyexceed the maximum or minimum specified limits, adjust the valve asfollows:

With the engine warmed up and running at approximately 2000RPM, observe the reading on the oil pressure gage. If the pressure isabove maximum or below minimum specified limits, stop engine andscrew the adjusting screw out to decrease pressure and in to increasepressure. Depending on installation, the adjusting screw may have on-ly a screw driver slot and is turned with a screw driver; or may havethe screw driver slot plus a pinned .375-24 castellated nut and may beturned with either a screw driver or a box wrench.

4. CYLINDER ASSEMBLY. Although the complete procedure fordisassembly and reassembly is given here, it is recommended that, as afield operation, cylinder maintenance be confined to replacement of theentire assembly. Valve replacement should be undertaken only as anemergency measure.

a. Removal of Cylinder Assembly -

(1) Remove exhaust manifold.

(2) Remove rocker box drain tube, intake pipe, priming lines and anyclips that interfere with the removal of cylinder.



(3) Disconnect ignition cable at spark plugs and remove spark plugs.Remove rocker box cover and rotate crankshaft until piston isapproximately at top center of the compression stroke.

(4) Remove valve rockers by sliding the valve rocker shaft asideenabling the valve rockers to be removed. Valve rocker shaft can beremoved when the cylinder is taken from the engine.

(5) Remove push rods by grasping the ball end and pulling rod out ofshroud tube.

(6) Remove cylinder base nuts and pull cylinder directly away fromthe crankcase. Do not allow the piston to drop against the crankcaseas the piston leaves the cylinder. Hold shroud tubes to prevent theirfalling.

NOTE

The tappets, push rods, rocker arms and valves must be identified sothat they can be assembled in the same location from which they wereremoved.

b. Removal of Valves and Valve Springs from Cylinder - Place thecylinder over a block of wood so as to hold the valves in a closed posi-tion. Compress the valve springs using the valve spring compressor.Remove the split keys from the end of the valve stem. The valve spr-ings and valve spring seats may now be removed from the cylinderhead. Hold the valve stems so that the valve will not fall out andremove the cylinder from the holding block. The valves may now beremoved from the inside of the cylinder.

c. Removal of Piston from Connecting Rod - Remove the piston pinplugs. Insert piston pin puller through piston pin, assemble puller nut;then proceed to remove piston pin. Do not allow connecting rod to reston cylinder pad of the crankcase. Support with heavy rubber bands,discarded cylinder base oil ring seals or any other method.

5-10



d Removal of Hydraulic Tappet Sockets and Plunger Assemblies -(0-290-D2 Series) It will be necessary to remove and bleed thehydraulic tappet plunger assembly so that dry tappet clearance can bechecked when the cylinder assembly is reinstalled. This is accomplish-ed in the following manner: A special Avco Lycoming tool is availablefor removal of the sockets and plunger assemblies. In the event thetool is not available, proceed as described below.

The hydraulic tappet socket may usually be removed by insertingthe forefinger into the concave end of the socket. The socket will usual-ly stick to the finger firmly enough to be pulled out of the tappet body.If the socket cannot be removed in this manner, it may be removed bygrasping the edge of the socket with a pair of needle nose pliers.However, care must be exercised to avoid scratching the socket. Toremove the hydraulic tappet plunger assembly, use special AvcoLycoming service tool. In the event that the tool is not available, thehydraulic tappet plunger assembly may be removed by bending a hookin the end of a short piece of lockwire, inserting the lockwire aroundthe edge of the plunger assembly, and turning the wire so that thehook engages the spring of the plunger assembly. Draw the plungerassembly out of the tappet body by gently pulling the wire.

CA UTION

Never use a magnet to remove hydraulic plunger assemlies from thecrankcase. This can cause the check ball to remain off its seat renderingthe unit inoperative.

e. Assembly of Valves in Cylinder - Prelubricate valve stems withMolytex Grease 0 or equivalent and insert each valve stem in itsrespective valve guide. Place cylinder over a block of wood so that thevalves are held against the seats and assemble the lower valve springseat, auxiliary valve seat and outer valve spring over the valve stemand guide. Place the upper valve spring seat on top of the springs.

NOTE

When installing valve springs, place the dampener end of spring (closewound coils marked with dye or lacquer) toward the cylinder.



Using a valve spring compressor, compress the valve springs andplace the split keys in the groove around the upper end of the valvestem. Slowly release the pressure on the valve spring compressor andallow the upper spring seat to lock itself in place around the valvekeys.

f Assembly of Hydraulic Tappet Plunger Assemblies - (0-290-D2Series) To assemble the unit, unseat the ball by inserting a thin cleanbronze wire through the oil inlet hole. With the ball off its seat, insertthe plunger and twist clockwise so that the spring catches.

g. Assembly of Cylinder and Related Parts - Rotate the crankshaft sothat the connecting rod of the cylinder being assembled is at the topcenter position with both tappets on the low side of the cam in a posi-tion that corresponds with both valve closed.

(1) 0-290-D2 Series - Place each hydraulic tappet plunger assembly inits respective body and assembly socket on top of plunger assembly.

(2) Assemble piston so that the cylinder number stamped on thepiston pin boss is toward the front end of the engine. The piston pinshould be a push fit. If difficulty is experienced in inserting thepiston pin, it is probably caused by carbon or burrs in the piston pinhole. During assembly, always use a generous amount of oil, both inthe piston pin hole and on the piston pin.

(3) Assemble one piston pin plug at each end of the piston pin andplace a new cylinder base oil seal ring around the cylinder skirt. Coatpiston, rings and the inside of the cylinder generously with oil.

(4) Using a piston ring compressor, assemble the cylinder over thepiston so that the intake and exhaust ports are toward the bottom ofthe engine.

(5) Push the cylinder down onto the cylinder mounting studs.

(6) Insert a new shroud tube oil seal over each end of shroud tube.

(7) Pull the cylinder back far enough to insert one end of each shroudtube into position in the cylinder head, and hold shroud tube so thatrubber seals will enter the seal seats in the crankcase. Push thecylinder all the way down.



NOTE

Before installing cylinder base hold down nuts, lubricate the crankcasethru-stud threads with any one of the following lubricants.

1. 90% SAE 50W engine oil and 10% STP.

2. Parker Thread Lube.

3. 60% SAE 30W engine oil and 40% Parker Thread Lube.

(8) Assemble the cylinder base hold down nuts and tighten asdirected in the following steps.

NOTE

At anytime a cylinder is replaced, it is necessary to retorque the thru-studs on the cylinder on the opposite side of the engine.

(a) Tighten the 1/2 inch or 7/16 inch hold down nuts to 300 inchpounds (25 foot pounds) torque in the following sequence: Beginwith the upper right hand nut and proceed in a clockwise direction.

(b) Repeat the above steps and tighten the 1/2 inch hold down nutsto 600 inch pounds (50 foot pounds) or 7/16 inch hold down nuts to420 inch pounds (35 foot pounds) torque using the exact sequencestated.

(c) Tighten the 3/8 inch hold down nuts to 300 inch pounds (25 footpounds) torque; sequence of tightening is optional.

NOTE

Some 0-235 Series engines employ only 3/8 inch hold down nuts. Tightenthese nuts to 300 inch pounds (25 foot pounds) torque using the tighten-ing sequence stated in step (a).

(d) As a final check hold the torque wrench on each nut for aboutfive seconds. If the nut does not turn, it may be presumed to betightened to the correct torque.

5-13



CAUTION

After all cylinder base nuts have been tightened remove any nicks in thecylinder fins by filing or burring.

(9) Assemble each push rod in its respective shroud tube, andassemble each rocker in its respective position by placing rockerbetween bosses and sliding valve rocker shaft in place to retainrocker.

(10) 0-290-D2 Series - Be sure that the piston is at top center com-pression stroke and that both valves are closed. Check clearance bet-ween the valve stem tip and the valve rocker. In order to check thisclearance, place the thumb of one hand on the valve rocker directlyover the end of the push rod and push down so as to compress thehydraulic tappet spring. While holding the spring compressed,check valve clearance, which should be between .028 and .080 inch.If the clearance does not come within these limits, remove the pushrod and insert a longer or shorter push rod, as required to correctclearance.

NOTEInserting a long rod will cause a decrease in valve clearance.

(11) 0-235, 0-290D Series - Be sure that the piston is at top centercompression stroke and that both valves are closed. Assembleadjusting screw in valve rockers and using clearance gage adjust theclearance between the valve tip and valve rocker. Adjust in thefollowing manner:

Set tappets with .007 in. - .009 in. clearance cold. Recheck tappetclearance after run-in, clearance should be from .006 in. to .012 in.After adjusting, lock the adjusting screw in place with the locknut.

(12) All Engines - Install gaskets and rocker box covers, intake pipes,drain tubes and exhaust manifold. Install spark plugs and ignitionharness.

5. GENERATOR DRIVE BELT TENSION. Check the tension of a newbelt 25 hours after installation. Refer to Service Instruction No. 1129 formethods of checking generator drive belt tension.


TROUBLE-SHOOTING

Page

Failure of Engine to Start ................................ 6-1Failure of Engine to Idle Properly ......................... 6-2Low Power and Uneven Running .......................... 6-2Failure of Engine to Develop Full Power ................... 6-3Rough Engine .......................................... 6-3Low Oil Pressure ....................................... 6-4High Oil Temperature .................................. 4Excessive Oil Consumption ............................. 6-5Cold Weather Difficulties ................................ 6-Engine Does Not Stop ................................ .6



SECTION 6

TROUBLE-SHOOTING

General - Experience has proven the best method of "trouble-shooting"is to decide on the various possible causes of a given trouble and then toeliminate these causes one by one, beginning with the most probable.The following chart lists some of the more common engine troublesusually found in maintaining aircraft engines.

TROUBLE PROBABLE CAUSE REMEDY

Failure of Engineto Start

Lack of fuel Check fuel system forleaks. Fill fuel tank. Cleandirty lines, strainers orfuel cocks.

Underpriming

Overpriming

Incorrect throttlesetting

Defective sparkplugs

Defective battery

Improper operationof magneto breakerpoints

Water in carburetor

Prime with engine primingsystem.

Open throttle and "unload"engine.

Set at 1/4 open position.

Clean and adjust or replacespark plug or plugs.

Replaced with chargedbattery.

Clean points. Check inter-nal timing of magnetos.

Drain carburetor and fuellines.

6-1



TROUBLE

Failure of Engineto Start (Cont.)

PROBABLE CAUSE REMEDY

Internal failure Check oil sump strainerfor metal particles. Iffound, complete overhaulof engine is indicated.

Failure of Engine Incorrect carburetor Adjust throttle stop toto Idle Properly idle adjustment obtain correct idle.

Idle mixture

Leak in the induc-tion system

Low cylindercompression

Insufficient spark

Adjust mixture.

Tighten all connections ininauction system. Replaceany parts that are defec-tive.

Check condition of pistonrings, and valves.

Check entire ignitionsystem.

Check primer shut-offvalve for leakage. Read-justment of carburetor byauthorized personnel isindicated.

Low Power andUneven Running

Mixture too rich;indicated by sluggishengine operation,red exhaust flame atnight. Extreme casesindicated by blacksmoke from exhaust.

Mixture too lean;indicated by over-heating or back-firing.

Leaks in inductionsystem

Defective sparkplugs

Poor fuel

Check fuel lines and filtersfor dirt or other restric-tions. Readjustment ofcarburetor is indicated.

Tighten all connections.Replace defective parts.

Clean or replace sparkplugs.

Fill tank with fuel ofrecommended grade.




Low Power andUneven Running(Cont.)

Magneto breakerpoints not workingproperly

Defective ignitionwire

Improper ignitiontiming

Defective sparkplug terminalconnectors

Incorrect valveclearance

Clean points. Check inter-nal timing of magnetos.

Check wire with electrictester. Replace any defec-tive wire.

Check magnetos for timingand synchronization.

Replace connectors onspark plug wire.

Adjust valve clearance.

Failure of Engineto Develop FullPower

Throttle lever outof adjustment

Adjust throttle lever.

Leak in the induc-tion system

Restriction incarburetor airscoop

Improper fuel

Faulty ignition

Tighten all connections,and replace defectiveparts.

Examine air scoop andremove restrictions.Clean air filter.

Fill tank with recom-mended fuel.

Tighten all connections.Check system with tester.Check ignition timing.

Replace mount.Rough Engine Cracked enginemount.

Unbalancedpropeller

Remove propeller and haveit checked for balance.

6-3


SECTION 6

TROUBLE

Rough Engine(Cont.)

Low Oil Pressure

High OilTemperature


PROBABLE CAUSE REMEDY

Defective mounting Install new mountingbushings bushings.

Malfunctioning Check entire engine.engine

Insufficient oil Fill sump to proper levelwith oil of recommendedgrade.

Air lock or dirt in Remove and clean oilrelief valve pressure relief valve.

Leak in suction line Check gasket betweenor pressure line. accessory housing and

crankcase.

Dirty oil strainers Remove and clean oilstrainers.

High oil See "High Oil Temp-temperature erature" in "Trouble"

column.

Defective pressure Replace gage.gage.

Stoppage - oil pump Check line for obstructionintake passage Clean suction strainer.

Insufficient air Check air inlet and outletcooling for deformation or

obstruction.

Insufficient oil Fill oil sump to propersupply level with oil of recom-

mended grade.

Low grade of oil Replace with oil conform-ing to specification.

Clogged oil lines orstrainers

Remove and clean oilstrainers.




High OilTemperature(Cont.)

Excessive blow-by

Failing or failedbearing

Defective tempera-ture gage

Low grade of oil

Usually caused by wornor stuck rings. Completeoverhaul required.

Examine sump for metalparticles. If found, com-plete overhaul of engines indicated.

Replace gage.

Excessive OilConsumption

Failing or failedbearing

Worn piston rings.

Incorrect instal-lation of pistonrings

Cold oilCold WeatherDifficulties

Fill tank with oil conform-ing to specification.

Check sump to metalparticles.

Install new rings.

Install new rings.

Move aircraft into aheated hangar. Heat oil.

In extreme cold weather,oil pressure readings upto approximately 100 lbs.do not necessarily indicatemalfunctioning.

Install fully chargedbattery.

Leave throttle open andignition "off". Put mixturecontrol in "Idle Cut-Off"and crank until enginestarts. Immediately returnto "full rich" mixture.

Inaccurate pres-sure readings

Weak battery

Overpriming




Engine DoesNot Stop

Linkage does notpermit full travelof "Idle Cut-Off"

Readjust linkage for fulltravel.

Leaking"Idle Cut-Off"

Faulty ignitionswitch

Overhaul carburetor.

Check ground wires,overhaul switch.



Page

Preparation of Engine for Installation ..................... 7-1

General .................. ........................... 7-2Inspection of Engine Mounting ......................... 7-2Attaching Engine to Mounts ........................... 7-2Oil and Fuel Line Connection ........................... 7-2Propeller Installation .................................. 7-2

Preparation of Carburetor for Installation ................. 7-2

Corrosion Prevention in Engine Installedin Inactive Aircraft ................................ 7-3

Installation Drawing ................................. 7-5



SECTION 7


1. PREPARATION OF ENGINE FOR INSTALLATION. Before in-stalling an engine that has been prepared for storage, remove alldehydrator plugs, bags of dessicant and preservative oil from the engine.Preservation oil can be removed by removing the bottom spark plugsand turning the crankshaft three or four revolutions by hand. Thepreservative oil will then drain through the spark plug holes. Drainingwill be facilitated if the engine is tilted from side to side during the aboveoperation. Preservative oil which has accumulated in the sump can bedrained by removing the oil sump plug. Engines that have been stored ina cold place should be removed to an environment of at least 70°F. (21°C.)for a period of 24 hours before preservative oil is drained from thecylinders. If this is not possible, heat the cylinders with heat lampsbefore attempting to drain the engine.

After the oil sump has been drained, the plug should be replaced,safety-wired, and the sump refilled with lubricating oil. The crankshaftshould again be turned several revolutions to saturate the interior of theengine with the clean oil. When installing spark plugs, make sure thatthey are clean, if not, wash them in clean petroleum solvent. Of course,there will be a small amount of preservative oil remaining in the engine,but this can cause no harm. However, after twenty-five hours of opera-tion, the lubricating oil should be drained while the engine is hot. Thiswill remove any residual preservative oil that may have been present.

CAUTION

Do not rotate the crankshaft of an engine containing preservative oilbefore removing the spark plugs, because if the cylinders contain ap-preciable amount of mixture, the resulting action, known as hydraulic-ing, will cause damage to the engine. Also, any contact of the preser-vative oil with painted surfaces should be avoided

7-1



General - Should any of the dehydrator plugs, containing crystals ofsilica-gel or similar material, be broken during their term of storage orupon their removal from the engine, and if any of the contents should fallinto the engine, that portion of the engine must be disassembled andthoroughly cleaned before using the engine. The oil strainers should beremoved and cleaned in gasoline or some other hydrocarbon solvent. Thefuel drain screen located in the fuel inlet of the carburetor should alsobe removed and cleaned in a hydrocarbon solvent. The operator shouldalso note if any valves are sticking. If they are, this condition can beeliminated by coating the valve stem generously with a mixture ofgasoline and lubrication oil.

Inspection of Engine Mounting - If the aircraft is one from which anengine has been removed, make sure that the engine mount is not bent ordamaged by distortion or misalignment as this can produce abnormalstresses within the engine.

Attaching Engine to Mounts - See airframe manufacturer's recommen-dations for method of mounting the engine.

Oil and Fuel Line Connections -The oil and fuel line connections are call-ed out on the accompanying installation drawings.

Propeller Installation - Consult the airframe manufacturer for informa-tion relative to propeller installation.

2. PREPARATION OF CARBURETORS FOR INSTALLATION.

Carburetors that have been prepared for storage should undergo thefollowing procedures before being placed in service.

Carburetor - Remove the fuel drain plug and drain preservative oil.Remove the fuel inlet strainer assembly and clean in a hydrocarbon sol-vent. Reinstall the fuel drain plug and fuel inlet strainer assembly.



CORROSION PREVENTION IN ENGINES INSTALLEDIN INACTIVE AIRCRAFT

Corrosion can occur, especially in new or overhauled engines, oncylinder walls of engines that will be inoperative for periods as brief astwo days. Therefore, the following preservation procedure is recom-mended for inactive engines and will be effective in minimizing the corro-sion condition for a period up to thirty days.

NOTE

Ground running the engine for briefperiods of time is not a substitute forthe following procedure; in fact, the practice of ground running will tendto aggravate rather than minimize this corrosion condition.

a. As soon as possible after the engine is stopped, move the aircraftinto the hangar, or other shelter where the preservation process is tobe performed.

b. Remove sufficient cowling to gain access to the spark plugs andremove both spark plugs from each cylinder.

c. Spray the interior of each cylinder with approximately (2) ounces ofcorrosion preventive oil while cranking the engine about five (5)revolutions with the starter. The spray gun nozzle may be placed ineither of the spark plug holes.

NOTE

Spraying should be accomplished using an airless spray gun (SprayingSystems Co., "Gunjet" Model 24A-8395 or equivalent). In the event anairless spray gun is not available, personnel should install a moisturetrap in the air line of a conventional spray gun and be certain oil is hot atthe nozzle before spraying cylinders.

d. With the crankshaft stationary, again spray each cylinder throughthe spark plug holes with approximately two ounces of corrosionpreventive oil. Assemble spark plugs and do not turn crankshaft aftercylinders have been sprayed.

7-3



The corrosion preventive oil to be used in the foregoing procedureshould conform to specification MIL-L-6529, Type 1 heated to200°F./220°F. (93°C./104C.) spray nozzle temperature. It is notnecessary to flush preservative oil from the cylinder prior to flying theaircraft. The small quantity of oil coating the cylinders will be expelledfrom the engine during the first few minutes of operation.

NOTE

Oils of the type mentioned are to be used in Avco Lycoming aircraft forcorrosion prevention only, and not for lubrication. See the latest editionof A vco Lycoming Service Instruction No. 1014 and Service Bulletin No.318 for recommended lubricating oil.

7-4

-MANIFOLD PRESSURE CONNPRIMER CONN.

z00

PRIMER OR MANIFOLDPRESSURE CONNECTION

OIL SUCTION SCREEN CARB. MOUNTING PAD

OIL DRAIN PLUG

Figure 7-1. Installation Drawing - Left Side View

GROUND TERMINAL

OIL SUCTION SCREEN

Figure 7-2. Installation Drawing - Rear View

MAGNETO S4LN-21 MAGNETO S4LN-20

GROUND TERMINALS -

VIEW SHOWING S4LN-20 8 S4LN-21 (IMPULSE) MAGNETOS

FUEL INLET

THROTTLE CLOSED

.85° IDLE CUT OFF

ANGULAR POSITION OF THROTTLE RICHMAY BE CHANGED TO SUIT INSTALLATION Z

64° CVIEWS OF CARBURETOR

Figure 7-3. Installation DrawingsFigure 7-3. Installation Drawings


TABLES

Page

Table of Limits ......................................... 8-1

Inspection Forms

After Top Overhaul or Cylinder Change with New RingsGround Run ........................................ 8-2Flight Test ......................................... 8-3

Full Throttle HP at Altitude ............................. 8-4Table of Speed Equivalents .............................. 8-4Centigrade Fahrenheit Conversion Table ................... 8-5Inch Fraction Conversions ............................... 8-6



SECTION 8

TABLES

FOR TIGHTENING TORQUE RECOMMENDATIONS AND IN-

FORMATION CONCERNING TOLERANCES AND DIMENSIONS

THAT MUST BE MAINTAINED IN AVCO LYCOMING AIRCRAFT

ENGINES, CONSULT LATEST EDITION OF SPECIAL SERVICE

PUBLICATION NO. SSP1776.

CONSULT LATEST EDITION OF SERVICE INSTRUCTION NO.

1029 AND NO. 1150 FOR INFORMATION PERTINENT TO COR-

RECTLY INSTALLING CYLINDER ASSEMBLY.

8-1

Time

5 min10 min10 min5 min5 min5 min5 min

RPMMAP

1000120013001500160017001800

Temperatureoil I cyl

R

FIXED WING ONLY

GROUND RUN AFTER TOP OVERHAUL Type AircraftOR CYLINDER CHANGE WITH NEW RINGS(DO NOT USE AFTER MAJOR OVERHAUL) Registration No.

1. Avoid dusty location and loose stones. Aircraft No.2. Head aircraft into wind.3. All cowling should be in place, cowl flaps open. Owner4. Accomplish ground run in full flat pitch.5. Never exceed 200°F. oil temperature. Engine6. If cylinder head temperatures reach 400°F.,

shut down and allow engine to cool before S/Ncontinuing.

Run-Up

GROUND RUN

ft No.

Model

Date

p By

oilL

Pressurefuel

R L

Temperaturecarb Amb.

R Air

z

Fuel Flow

GroundRun

ect engine(s)el(s)

Mag. Check

Power Check

Idle Check

Adjustment Required After Completion of

1. Visually inspi2. Check oil lev

FLIGHT TEST AFTER TOP OVERHAULOR CYLINDER CHANGE WITH NEW RINGS

1. Test fly aircraft one hour.2. Use standard power for climb, and at least 75% power for cruise.3. Make climb shallow and at good airspeed for cooling.4. Record engine instrument readings during climb and cruise.

Tested by

FLIGHT TEST RECORD

RPM TemperatureTime MAP oil cy

L R L R(Climb)

Cruise

Adjustments Required After Flight

Pressure Temperature Fuel Flowoil fuel carb Amb.

L R L R L R Air L R

After Test Flight

1. Make careful visual inspection of engine(s).2. Check oil level(s).3. If oil consumption is excessive, (see operator'smanual for limits), remove spark plugs and checkcylinder for scoring.

0

m0



FULL THROTTLE HP AT ALTITUDE(Normally Aspirated Engines)

Altitude % S. L. Altitude % S. L. Altitude % S. L.Ft. H. P. Ft. H. P. Ft. H. P.

0500

1,0002,0002.5003,0004,0005,0006,0007,0008,0009,000

10098.596.893.692.090.587.584.681.778.976.273.5

10,00011,00012,00013,00014,00015,00016,00017,00017,50018,00018,50019,000

70.868.365.863.461.058.756.554.353.152.151.450.0

19,50020,00020,50021,00021,50022,00022,50023,00023,50024,00024,50025,000

49.148.047.646.045.244.043.342.241.440.339.538.5

TABLE OF SPEED EQUIVALENTS

Sec./Mi. M. P. H. Sec./Mi. M. P. H. Sec./Mi.

72.060.051.445.040.036.032.730.027.725.7

5060708090

100110120130140

24.022.521.220.018.918.017.116.415.615.0

150160170180190200210220230240

14.413.813.312.812.412.011.611.210.910.6

M. P. H.

250260270280290300310320330340

8-4



CENTIGRADE-FAHRENHEIT CONVERSION TABLE

Example: To convert 20°C. to Fahrenheit, find 20 in the center columnheaded (F-C); then read 68.0°F. in the column (F) to the right. To convert20°F. to Centigrade; find 20 in the center column and read -6.67°C. in the(C) column to the left.

C F-C F C F-C F

56.7 -70 -94.0 104.44 220 428.0-51.1 -60 -76.0 110.00 230 446.0-45.6 -50 -58.0 115.56 240 464.0-40.0 -40 -40.0 121.11 250 482.0-34.0 -30 -22.0 126.67 260 500.0-28.9 -20 -4.0 132.22 270 518.0-23.3 -10 14.0 137.78 280 536.0-17.8 0 32.0 143.33 290 554.0

-12.22 10 50.0 148.89 300 572.0-6.67 20 68.0 154.44 310 590.01.11 30 86.0 160.00 320 608.04.44 40 104.0 165.56 330 626.0

10.00 50 122.0 171.11 340 644.015.56 60 140.0 176.67 350 662.021.11 70 158.0 182.22 360 680.026.67 80 176.0 187.78 370 698.032.22 90 194.0 193.33 380 716.037.78 100 212.0 198.89 390 734.043.33 110 230.0 204.44 400 752.048.89 120 248.0 210.00 410 770.054.44 130 266.0 215.56 420 788.060.00 140 284.0 221.11 430 806.065.56 150 302.0 226.67 440 824.071.00 160 320.0 232.22 450 842.076.67 170 338.0 237.78 460 860.082.22 180 356.0 243.33 470 878.087.78 190 374.0 248.89 480 896.093.33 200 392.0 254.44 490 914.098.89 210 410.0 260.00 500 932.0

8-5

SECTION 8



INCH FRACTIONS CONVERSIONSDecimals, Area of Circles and Millimeters

Inch Decimal Area MM InchFraction Equiv. Sq. In. Equiv. Fraction

1/64 .0156 .0002 .397 1/21/32 .0312 .0008 .794 17/323/64 .0469 .0017 1.191 35/64

1/16 .0625 .0031 1.587 9/163/32 .0937 .0069 2.381 19/32

7/64 .1094 .0094 2.778 39/641/8 .125 .0123 3.175 5/8

5/32 .1562 .0192 3.969 21/3211/64 .1719 .0232 4.366 43/64

3/16 .1875 .0276 4.762 11/167/32 .2187 .0376 5.556 23/32

15/64 .2344 .0431 5.593 47/641/4 .25 .0491 6.350 3/4

9/32 .2812 .0621 7.144 25/3219/64 .2969 .0692 7.540 51/64

5/16 .3125 .0767 7.937 13/1611/32 .3437 .0928 8.731 27/32

23/64 .3594 .1014 9.128 55/643/8 .375 .1105 9.525 7/8

13/32 .4062 .1296 10.319 29/3227/64 .4219 .1398 10.716 59/64

7/16 .4375 .1503 11.112 15/1615/32 .4687 .1725 11.906 31/32

31/64 .4844 .1842 12.303 63/64

Decimal Area MMEquiv. Sq. In. Equiv.

.5 .1964 12.700

.5312 .2217 13.494

.5469 .2349 13.891

.5625 .2485 14.288

.5937 .2769 15.081

.6094 .2916 15.478

.625 .3068 15.875.6562 .3382 16.669.6719 .3545 17.065.6875 .3712 17.462.7187 .4057 18.256.7344 .4235 18.653.75 .4418 19.050.7812 .4794 19.844.7969 .4987 20.241.8125 .5185 20.637.8437 .5591 21.431.8594 .5800 21.828.875 .6013 22.225.9062 .6450 23.019.9219 .6675 23.416.9375 .6903 23.812.9687 .7371 24.606.9844 .7610 25.003

60297-9 - operator's manual - o-235 and o -...

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