KZ750GT tapping noise in top end driving me nuts !

Can someone help me ?The bike has a tapping noise which sounds like it is in the top end.If you place your head on the tank at idle,it sound exactly like a one valve with excessive clearence which hammmers away louder as the revs increase.I booked the bike into a dealer to get the valve clearences done.He found a couple of tight valves but nothing with excessive clearence.
It runs like a dream now apart from the noise which is still there.
I pulled the auto tensioner out and was delighted to find it was locked up solid.I polished the faces of the wedge contact surfaces cleaned and reassembled it and made sure it was working correctly,thinking it would be problem solved.It was not.
All I can think of now is the cam chain has stretched enough to be beyond the range of the auto tensioner and maybe a manual one would do the trick?
Having said all of that,it does not really sound like cam chain rattle anyway.
Any ideas or suggetions would be appreciated.The bike has 68000ks on it.

Has the exhaust been removed from the head recently? Most "valve clatter" is actually exhaust leaks.

RonKZ650 wrote:

Has the exhaust been removed from the head recently? Most "valve clatter" is actually exhaust leaks.

Sounds crazy, but it is true. The same happened to me. I had swapped exhaust without changing the crush gaskets. The noise sounded exactly like a metal tapping, but was an exhaust leak.
Can you disconnect one of the plugs at a time while the engine is running to see if the noise stops?

Thanks for help.Checked carefully but not exhaust leaking.I have to assume the dealer checked clearences correctly but it sure sounds like it is valve related.Can a slack cam chain make a noise similar to this?
:dry:

Yeah, mine has this rapping noise when cold and a guy who checked out my bike told me it could be the cam chain. I bought a manual chain tensioner to see if that will help also. I dont know if it will work yet because the engine isn't put together yet.

Oh man...I've got the same top end noise. Hoping its just the exhaust gaskets. Thanks guys for saving me a trip inside the head...I hope.

highspeedjelly wrote:

...assume the dealer checked clearences correctly....

Don't bet the farm. :ohmy: