I am working on a 1990 zx 7 I bought a couple months ago. it does have 29000 miles on it but runs great. the only problem is a noise sounds like a vibration noise when the engine is turning around 3000 rpm I have checked everything I can think of but can't find anything loose. seems like it may be coming from the engine but when the engine is under load or turning below 3000 or over 3 or 3500 rpm the vibration noise is gone. has anyone else had this problem? any help would be great

 

only on a suzuki lt80 quad and it was the rubber motor mounts and the rubber bushings that had gotten a little weathered.

 

Not that issue yet on my 90 zx-7. Speaking of mounts, you have the solid mounts up top?

 

29,000 tim eto check your valaves Also which side of the motor, if it sounds like the rt side you may want to check the cam chain tensioner.

 

Also; some times the fuel tank can touch the frame where the rubber has weathered.This can also make a vibration which sounds like it is coming from the motor.