Stihl MS 241 C-M Instruction Manual - Page 30

English Checking Chain Tension N Shut off the engine. N Wear work gloves to protect your hands. N The chain must fit snugly against the underside of the bar and it must still be possible to pull the chain along the bar by hand when the chain brake is released. N If necessary, retension the chain. A new chain has to be retensioned more often than one that has been in use for some time. N Check chain tension frequently - see chapter on "Operating Instructions". 142BA064 KN Fuel This engine is certified to operate on unleaded gasoline and STIHL twostroke engine oil at a mix ratio of 50:1. Your engine requires a mixture of highquality gasoline and two-stroke air cooled engine oil. Use mid-grade unleaded gasoline with a minimum octane rating of 89 (R+M/2) and no more than 10% ethanol content. 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 high-quality unleaded gasoline! 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 HP Ultra 2-Cycle Engine Oil since it is specially formulated for use in STIHL engines. Do not use BIA or TCW rated (twostroke 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, chain saws, 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 container from your vehicle and place the container on the ground before filling. To reduce the risk of sparks from static discharge and resulting fire and/or explosion, do not fill fuel containers that are sitting in or on a vehicle or trailer. The container should be kept tightly closed in order to limit the amount of any moisture that gets into the mixture. The machine's fuel tank should be cleaned as necessary. Fuel mix ages Only mix sufficient fuel for a few days work, not to exceed 30 days of storage. Store in approved fuel-containers only. When mixing, pour oil into the container first, and then add gasoline. Close the container and shake it vigorously by hand to ensure proper mixing of the oil with the fuel. Gasoline Oil (STIHL 50:1 or equivalent high-quality oils) US gal. 1 2 1/2 5 US fl.oz. 2.6 6.4 12.8 Dispose of empty mixing-oil containers only at authorized disposal locations. 28 MS 241 C-M