Stihl 066 Instruction Manual - Page 44

Checking and Replacing Chain Sprocket 6 001BA104 ST 137BA020 KN Release the rotor - •• Let go of rope slowly so that it winds onto the rotor. • The starter grip must sit firmly in the rope guide bush. If the grip droops to one side: Increase spring tension by one additional turn. • When starter rope is fully extended it must be possible to rotate the rotor at least another half turn. If this is not the possible, the spring is overtensioned and could break Take off one turn of the rope. • Fit the fan housing on the crankcase. • Set the Master Control lever to Push the remaining rope into the starter grip so that the nipple (6) is flush with the grip. Replacing a broken rewind spring • Lubricate the new spring with a few drops of non-resinous oil - • Remove the rope rotor see "Replacing Starter Rope" - The bits of spring in the fan housing might still be under tension and could fly apart when you take them out of the housing. To avoid risk of injury, wear eye and face protection and work gloves. • Remove the spring housing and parts of spring. • Fit the new spring housing bottom plate must face upward slip outer spring loop over lug - • Reinstall the rope rotor, tension the rewind spring, fit the fan housing and secure it in position. If the spring pops out of its housing during installation: refit it in the counterclockwise direction, starting outside and working inward. Replace the chain sprocket after using two Oilomatic chains or sooner if the wear marks on the sprocket are deeper than approx. 0.5 mm (1/64") since this would reduce the life of the chain. Check wear marks: Left: on webs of rim sprockets - Right: on teeth of spur sprockets. You can use gauge* 0000 893 4101 to check the depth of the wear marks on spur and rim sprockets. It is best to use two chains in rotation with one sprocket. Before removing chain sprocket Remove chain sprocket cover, chain and guide bar. Disengage the chain brake: Pull hand guard toward front handle. *Special accessory 42 066