Stihl MS 360 ChainsawCeline Colbert

Figure 1 Photo courtesy of Stihl USA

IntroductionThis is a description of a Stihl MS 360 professional chainsaw for individuals or corporations shopping for chainsaws. A professional chainsaw differs from a homeowners or mid-grade chainsaw in that it is designed for more constant use. Because of this, repairs are often easier with the capability of replacing smaller segments of parts. Also the exterior tends to contain more metal components to withstand more wear and tear than plastic coverings. The professional chainsaws, also, tend to come in models with more power than the less frequently used homeowners and mid-range chainsaws.

The Stihl MS 360 professional chainsaw weighs 12.6 pounds without its bar and chain. It has a 1.32 pint fuel tank and a 0.68 pint lubricating oil tank, and it is compatible with 16, 18, or 20 inch cutting bars. This chain saw is powered by a Stihl single-cylinder, two-stroke engine. The engine has a displacement of 3.75 cubic inches and a 1.89-inch bore. It produces a stroke of 1.34 inches and a maximum speed of 2800 RPM.

Figure 2 Diagram of the Stihl MS 360

Safety Features and Their Function

Chain Brake/ Front Hand GuardOne of the most important safety features of the Stihl 360 is the chain brake. This component once engaged via the front hand guard, prevents the chain from spinning around the bar. It does much like a brake does in a car by applying pressure to the clutch drum the way a car applies brakes to the wheels. This violent stopping of the chain can be hard on the chain brake and clutch drum. This is why most knowledgeable experts recommend releasing the throttle and allowing the saw to return to idle before engaging the brake to allow a less violent stopping then when the saw is at full power. While the chain brake is engaged the throttle can be applied, however the chain will not spin.

Wide Rear HandleThis is a safety feature found on most modern chainsaws. It can be seen below shown by the number 23. Its function is to protect the throttle operating hand in the event that the chain is thrown from the bar.

Chain Catch PegThe chain catch peg is label as 7 above. It is a small but very strong piece of metal that acts as a safety device. It operates in much the same way as the wide rear handle in that it provides a defense in the event that the chain being thrown from the bar. If the chain were to be thrown it provides the first line of defense in catching the chain so that it does not violently whip back and hurt the operator. It should be checked regularly to assure that it has not accidently broken off as it protrudes from the main head and is therefore more susceptible to damage.

Chain TensionerThe chain tensioner which is shown by number 8 in the illustration above is a very integral part of the saw. It controls how tightly the chain is held to the saw. If a chain is too tight it may be prevented from properly spinning around the saw or cause excess wear and damage to the chain or guide bar. Additionally if a chain is too loose it may jump the guide bar which can cause damage to the guide bar, chain, and rim sprocket of the saw. A loose chain also possess a greater likelihood of being thrown from the saw which could potentially cause the operator bodily harm. The chain tensioner is a screw that is operated by either tightening or loosening the screw to the desired tension. A general rule of thumb when tensioning a saw is to be able to pull the chain up so that u could slide a dime between the drive link and the guide bar.

Throttle InterlockThe throttle interlock is labeled as 21 above. It operates as a safety mechanism against accidently engaging the throttle, or the throttle potentially becoming stuck while engaged.

In order to engage the throttle both the throttle and the throttle interlock must be depressed. It is a feature found on most modern chainsaws but is absent on early models.

Bumper SpikesBumper spikes or “dogs” as they are commonly referred to, provide another helpful safety feature on a saw, and are labeled in the illustration above as number 9. While these sharp pointed metal plates could easily pierce your skin, they help control the saw greatly when cutting. They serve to pierce the wood and allow you to rotate the saw around the dogs as a pivot point. This helps combat “kickback” forces which can cause the saw to violently jump back at a user, however with these metal spikes embedded in the wood the saw cannot move as freely.

Handle Heating SwitchThe handle heating switch shown in the illustration above as number 3 provides a bit of comfort to the chainsaw. In some newer model chainsaws you can choose the option to have a heated front handle on the saw. This can be a very nice feature on a cold winter day, and in certain cases can help prevent frostbite and fatigue. By keeping your hands warm they keep their dexterity which will allow the operator to run the saw more safely and efficiently.

Bar and Chain Elements

ChainThe chain of a chainsaw is composed of rakers, cutting teeth, and drive links. The rakers set the depth for the cutting tooth and control how much wood is removed by each tooth. It is important to file your rakers when you sharpen your chainsaw to allow for proper cutting. The cutting tooth is the sharp part of the chain that actually removes the wood, it is important to have sharp teeth that are filed at the same angle to ensure proper cutting performance. The drive link is the portion of the chain that moves through the guide bar and passes through the rim sprocket which gives the chain its speed and power when the throttle is engaged.

Figure 3 Example of a typical chainsaw chain

Drive Link

RakerTooth

Bar GuideThe chainsaw bar can be seen below. It guides the chain through the groves of its perimeter to allow for cutting. It is important to keep the groves of the bar as well as the oiling hole (not shown) clear of debris for optimal performance. Bars are available in varying lengths. The 16, 18, 20 inch Stihl bars are recommended for use on the MS 360. This will allow the user to comfortably fell up to a 40 inch diameter tree.

Figure 4 Stihl Rollomatic E bar guide with chain

Photo CreditsFigure 1 and 2: Stihl MS 360 owner’s manual

Figure 3: http://www.stihlusa.com/products/chain-saws/saw-chains/pmmc3/

Figure 4: http://www.euroshopy.eu/stihl-guide-bar-45-cm-rollomatic-e-2/