Checking Chain Tension

143BA007 KN

:Shut off the engine.

:Wear work gloves.

:Chain must fit snugly against the underside of the bar – and, with the chain brake disengaged, it must still be possible to pull the chain along the bar by hand.

:If necessary, retension the chain.

A new chain has to be retensioned more often than one that has been in use for some time.

Check chain tension frequently – see "Operating Instructions".

Fuel

This engine is certified to operate on unleaded gasoline and the STIHL two- stroke engine oil at a mix ratio of 50:1.

Your engine requires a mixture of high- quality gasoline and quality two-stroke air cooled engine oil.

Use mid-grade unleaded gasoline with a minimum octane rating of 89 (R+M/2). If the octane rating of the mid-grade gasoline in your area is lower, use premium unleaded fuel.

Fuel with a lower octane rating may increase engine temperatures. This, in turn, increases the risk of piston seizure and damage to the engine.

The chemical composition of the fuel is also important. Some fuel additives not only detrimentally affect elastomers (carburetor diaphragms, oil seals, fuel lines, etc.), but magnesium castings and catalytic converters as well. This could cause running problems or even damage the engine. For this reason STIHL recommends that you use only nationally recognized high-quality unleaded gasoline!

English / USA

Use only STIHL two-stroke engine oil or equivalent high-quality two-stroke engine oils that are designed for use only in air cooled two-cycle engines.

We recommend STIHL 50:1 two-stroke engine oil since it is specially formulated for use in STlHL engines.

Do not use BIA or TCW rated (two- stroke water cooled) mix oils or other mix oils that state they are for use in both water cooled and air cooled engines (e.g., outboard motors, snowmobiles, chainsaws, mopeds, etc.).

Take care when handling gasoline. Avoid direct contact with the skin and avoid inhaling fuel vapor. When filling at the pump, first remove the canister from your vehicle and place the canister on the ground before filling. Do not fill fuel canisters that are sitting in or on a vehicle.

The canister should be kept tightly closed in order to avoid any moisture getting into the mixture.

The machine‘s fuel tank and the canister in which fuel mix is stored should be cleaned as necessary.

MS 270, MS 270 C, MS 280, MS 280 C

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