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FUEL SYSTEM 3-25

5. SERVICING OF INJECTION NOZZLES

ANO NOZZLE HOLDERS

Q 1. BODYI~ -1 2. CYCRON BLADE2 3. ELEMENT

4. DUST PAN .

5. WING NUT

1. JOINTSOL;-r

2. OVERFLOW VALVE

3. JOINT SOL T

4. JOINT SO(,.T

5. COVER

6. ELEMENT

8_-

9

10

11~

l

.1. JOINTBOLT

2. GASKET

3. SCREW CAP NUT

4. GASKET

5. ADJUSTING SCREW

6. NUT

7. GASKET

8. WASHER

9. NOZZLE SPRING

10. PUSH.ROD

11. NOZZLE SPRING

12. SCREW NOZZLE HOLDER

13. NOZZLE

14. NOZZLE NUT

15. WASHER

16. CONNECTOR

17. EDGE FILTER

FIG. 3-66

Disassembly

12-

5-1

Clean the internai part of the nozzle body in

kerosene by using a piece of wood.

(1} Visual inspection

After washing, check the injection nozz(es

against the fo(lowing :

1) Needfe valves.Check the valve seats. guide shafts and injec-

tion shaft for damage. ;

2) Nozzle body.Check the valve seats for carbon deposit and

damage. Aiso check the injection orifices fbr

uneven wear.Replace both of the parts by using an as-

sembly even if either of the needfe valve or

the nozzle body is found to be defective.

(2) Sliding testA sliding test shou(d be made on the entire in-

jection nozzles often visual inspection.

Hold the nozzle body vertically and pull the nee-dle valve upward about 1/3 of its entire length

and release it and see if it lowers onto its seat by

its own weight.If lowering of the needle valve is unsmooth.

check for presence of foreign matter and repeat

the test.If the trouble persists. replace the entire nozzle

assembly with a new one.

(3} Testing of injection nozzles on nozzle tester

Make the following tests by using a nozzle

tester .

a. (njection starting pressure.

b. Spray pattern and operating noise.

Exercise extreme care when handling the injection

nozzle assembly, partjcularly the nozzle body andneedle valves as these parts are ultra-precision-

finished.Wash clean the injection nozzle assembly removed

from the engine prior to disassembling.(1) Clamp the nozzle holder in a vise and remove the

cap nut.(2) Remove the adjust screw lock nut and remove

the adjust screw, then remove the spring. spring

seat and push-rod.(3) Clamp the nozzle holder body with the nozzle

side up in a vise.(4) With a wrench. remove the nozzle nut using care

not to drop the nozzle. Remove the nozzle care-fulJy not to drop the needle valve.

Inspection of injection nozzles-2

Wash clean the disassembled parts in clean

kerosene and insert the needle valve into the nozzle

body in new kerosene. If the needle valves are fouled

with carbon deposit, clean them in kerosene by

using a piece of wood and avoid the use of abrasive

particles and other metal cleaners. Keep fingersaway from the lapped portion of the needle valves. or

rust formation will result. FIG. 3-67