Motorcycle Repair: misfire at 5000-6000rpm, thrust washer, advancer

Question
Hi Bill, furthermore i broke down today while riding. I diagnosed and got going again myself. Problem was with the spark advancer, the knock pin that keeps the spark advancer in correct position is extremely loose and falls out once revs reach 5000 and above. I located the pin and put it back into position, the bike ran with the same misfire around 5000rpm. One thing i noticed in behind the advancer connected to the cam is an oil seal, in good order, then the knock pin (seems loose), then the advancer, point base and so on. No washer betwen oil seal and advancer, is there meant to be a washer there, could this possibly be causing erratic misfire??
Regards Jamie

Answer
Jamie.... The fixing bolt for the advancer should lock the unit to the end of the camshaft. The knock pin is just for alignment purposes. If the hole in the advancer or cam is worn out of round, the parts should be replaced, however try a new pin locate the approximate center of both holes, add some locktite to the camshaft hole to help anchor the pin and reassemble. The thrust washer on the fixing bolt should hold the center of the spark advancer firmly against the camshaft, so the only movement is in the springs/weights and point cam.

http://www.cmsnl.com/honda-cb500t-500-twin-dohc-1976-usa_model462/partslist/E++0...   There is no washer between seal and advancer. The friction would overheat and damage the seal immediately.

Bill Silver