Any ideas? 1994 Warrior. Completely stock, everything original. The bike has about 150 hours on it since new. When running the bike, the top end emmits a "buzzing" sound as the RPM increases. Valve clearance is right on. Sounds more like a timing chain issue. Any ideas on the life of a timing chain? Also, any way to adjust the tension of the chain? Also, whats the bolt on the lower left side of the cylinder head for? It has to do with the chain tensioner. Can it be adjusted at all? Thanks!

 

Yes, the bolt you described is a part of the timing chain tensioner, and it is automatic, but the Clymer's manual says to inspect the spring for wear, or bending, and to check the rack teeth.