Stihl 017 Instruction Manual - Page 31

Checking Chain Tension All Versions Turn 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 section "During Operation". 017, 018 143BA007 KN Fuel Mix This engine is certified to operate on unleaded gasoline and oil with the mix ratio 50:1. Your two-stroke engine requires a mixture of brand-name gasoline and quality two-stroke engine oil with the classification TC. Use regular branded unleaded gasoline with a minimum octane rating of 90 ROZ (U.S.A./Canada: pump octane min. 89!). If the octane number of the regular grade gasoline in your area is lower, use premium unleaded fuel. Fuel with a lower octane rating may result in preignition (causing "pinging") which is accompanied by an increase in engine temperature. 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 as well. This could cause running problems or even damage the engine. For this reason it is essential that you use only branded fuels! Use only STIHL two-stroke engine oil or equivalent branded two-stroke aircooled engine oils with the classification TC for mixing. We recommend STIHL 50:1 two-stroke engine oil since it is specially formulated for use in STIHL engines. Do not use BIA or TCW (two-stroke water cooled) mix oils! Take care when handling gasoline. Avoid direct contact with the skin and avoid inhaling fuel vapour (see "Safety Precautions"). The canister should be kept tightly closed in order to avoid any moisture getting into the mixture. The fuel tank and the canister in which fuel mix is stored should be cleaned from time to time. Fuel mix ages: Only mix sufficient fuel for a few days work, not to exceed 3 months of storage. Store in approved safety fuel-canisters only. When mixing, pour oil into the canister first, and then add gasoline. Gasoline Oil (STIHL 50:1 or equivalent branded TC oils) US gal. US fl.oz 1 2.6 2 1/2 6.4 5 12.8 Dispose empty mixing-oil canisters only at authorized disposal locations. 29