Release the chain brake. Back off the chain adjustment screw several turns and remove the two large cover nuts. Remove the drive cover, then pull the bar back toward you. This will allow the old chain to be removed. Remove the bar and clean the entire area where the bar mounted. Check the outside edges of the chain groove area for any flaring out of the bar metal due to wear. Use a flat file to cut off this flaring edge (at about 45 degrees) so that nothing projects beyond the bar vertical surface on both sides. Turn the bar upside down to even the wear in the chain groove. Clean the oil holes in the bar end including the small channels that bring oil from large holes out to the chain groove on each side and clean the entire chain groove. Insert the bar, then feed the new chain with the teeth on the lower run cutting toward you, onto the sprocket, then work it over the entire bar and pull the bar out as far as it will go. Install the cover (which has been cleaned too) and run the nuts on finger tight (make sure the adjustment tang dropped into a large hole at the bar rear). Turn the adjustment screw CW until the chain ceases to droop from the lower bar, but the chain can still be pulled by hand. Tighten the large nuts firmly and recheck chain tension--if ok, start the engine and hold the bar tip near a piece of cardboard while the engine runs at speed for several moments--you should get a thin line of oil thrown off onto the cardboard. Hope this helps!
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Release the chain brake. Back off the chain adjustment screw several turns and remove the two large cover nuts. Remove the drive cover, then pull the bar back toward you. This will allow the old chain to be removed. Remove the bar and clean the entire area where the bar mounted. Check the outside edges of the chain groove area for any flaring out of the bar metal due to wear. Use a flat file to cut off this flaring edge (at about 45 degrees) so that nothing projects beyond the bar vertical surface on both sides. Turn the bar upside down to even the wear in the chain groove. Clean the oil holes in the bar end including the small channels that bring oil from large holes out to the chain groove on each side and clean the entire chain groove. Insert the bar, then feed the new chain with the teeth on the lower run cutting toward you, onto the sprocket, then work it over the entire bar and pull the bar out as far as it will go. Install the cover (which has been cleaned too) and run the nuts on finger tight (make sure the adjustment tang dropped into a large hole at the bar rear). Turn the adjustment screw CW until the chain ceases to droop from the lower bar, but the chain can still be pulled by hand. Tighten the large nuts firmly and recheck chain tension--if ok, start the engine and hold the bar tip near a piece of cardboard while the engine runs at speed for several moments--you should get a thin line of oil thrown off onto the cardboard. Hope this helps!