i have a loud valve tap and was wondering if i threw a valve??? i've adjusted the valves countless times and that has done nothing. it's been tapping since i got it but not as bad as it is now. I've been meaning to rebuild the top end but never had the time to do it. any help would be great. thx

ps it got worse when i put it in reverse and pinned it lol which i know was a bad idea lol

 

What does your valve adjuster bolt look like?? They are soft on those Yamaha 350/400 engines and it could be that your bolt just needs replaced. I see it all the time.
And have you verified the noise is indeed the valve and not the timing chain? Those are a weak link on those engines as well when they start showing there age.

 

it's a 1/4 inch stud with a 10mm nut. it's not the timing chain cause i just replaced it a few months ago. and it's still nice and snug. i was just going to rebuild the whole top end from valves to piston (the works). but if i am going to do that is there a kit that comes with everything or do i have to buy everything seprate?

 

if i were you and rebuilt the top end i would go with JE 366 piston kit and kibblewhite vavles, D.I.D. timing chain, webb springs and cam if you want.