Stihl 066 Instruction Manual - Page 36

During Break-in Period During Operation After Finishing Work A factory new machine should not be run at high revs (full throttle off load) for the first three tank fillings. This avoids unnecessary high loads during the break-in period. As all moving parts have to bed in during the break-in period, the frictional resistances in the engine are greater during this period. The engine develops its maximum power after about 5 to 15 tank fillings. Do not make the mixture leaner to achieve an apparent increase in power - this could damage the engine - see section "Adjusting Carburetor". Note: Always disengage chain brake before accelerating engine and before starting cutting work. High revs with the chain brake engaged (chain locked) will quickly damage the powerhead and chain drive (clutch, chain brake). 34 Check chain tension frequently. A new chain has to be retensioned more often than one that has been in use for some time. Chain cold: Tension is correct when chain fits snugly against the underside of the bar and can still be pulled along the bar by hand. Retension if necessary see section "Tensioning the Saw Chain". Chain at operating temperature: The chain stretches and begins to sag. The drive links must not come out of the bar groove - the chain may otherwise jump off the bar. Retension the chain see section "Tensioning the Saw Chain". Always slacken off the chain after finishing work. The chain contracts as it cools down. If it is not slackened off, it can damage the crankshaft and bearings. After long period of full-throttle operation Allow engine to run for a short while at idling speed so that engine heat can be dissipated by flow of cooling air. This protects engine-mounted components (ignition, carburetor) from thermal overload. Slacken off the chain if you have retensioned it at operating temperature during cutting work. The chain contracts as it cools down. If it is not slackened off, it could damage the crankshaft and bearings. Before storing your saw for a long period - Drain and clean the fuel tank •• Run engine until carburetor is dry Storing the Machine For periods of about 3 months or longer: • Drain and clean the fuel tank in a well ventilated area. • Run engine until carburetor is dry this helps prevent the carburetor diaphragms sticking together. • Remove the saw chain and guide bar, clean them and protect with corrosion inhibiting oil. • Thoroughly clean the machine pay special attention to the cylinder fins and air filter. • If you use a biological chain lubricant (e.g. STIHL Bioplus), fill the chain oil tank. • Store the machine in a dry and high or locked location - out of the reach of children and other unauthorized persons. 066