This is not the easiest to explain but here goes I have a foreman that runs great except for when you rev the engine up or when you are driving at a certain rpm it starts making a ticking or taping noise pretty annoying...anyways I just rebuilt the bike bored out new piston, rings, timing chain the works engine does not smoke or make any other noise just when you rev it up or rev it to certian spot in each gear...I already adjusted the valves a couple of times I don't think that is the problem but I could be wrong Please help

 

make sure your timing chain tensioner is working properly

 

Do you know if I have to take the top end off the bike to check that? I can see where the adjuster is but it looks like you would have to the cylinder off.

 

take tensioner out and make sure it moves freely. i had one of these where the thing back fired so bad it screwed up tensioner and stretched timing chain making it jump time