release clutch, hear funny noise???

[92 z28]

hey, i have a 95 ex500. it has under 4k miles on it. recently ive begun to gear this funny noise when im reving while holding the clutch or releasing the clutch. its hard to explain the noise, but it kinda sounds like something tapping the gas tank from underneath, kinda like metal lightly tapping metal. anybody have ideas or experiences with this? let me know. thanks!!

[92 z28]

i meant HEAR not gear. my bad

[shift1313]

does this change the clutch feel at all? does it feel like its dragging or slipping? its probobly unrelated to the clutch and just a loose something some where. but if its affecting the clutch thats another story.

matt

[92 z28]

nop, the clutch feels just fine, but why would it only tap when the clutch is pulled back, or being engaged?

[shift1313]

It could be one of the cable guides that bolts down along the way. I would follow the noise if you. can hopefully its not something major, like first gear. just make the noise a few times and get as close to it as you can, maybe have someone off the bike look if its in a tough spot. since its very general there isnt really one thing i can tell you too look for.

sorry

[Curt]

Originally Posted by shift1313

its probobly unrelated to the clutch and just a loose something some where.

I agree. But those things can be hard to find (as you now know). Get yourself a small rubber hose (like a fuel hose from an auto shop). Stick one end in your ear and point the other end around the engine area while the bike is making the noise. Move the end of the hose around to find where the noise is the loudest. Then stick your fingers in there and try to find something loose.

The reason you hear it when the clutch is releasing or when the engine is revving is because of a physics principle called simple harmonic motion. The thing only rattles when the harmonics (vibrations) are at the right frequency. If you want an example, stand up a picture frame (the kind with glass in front of the picture) on top of a piano. Play different notes. Every note on the piano makes sound (vibrations) at a different frequency. You'll find a few notes (typically about four to six) that will make the picture rattle. None of the other notes will bother it at all. Your bike works the same way. When you get the frequency just right, the loose thing will rattle.
Curt

[92 z28]

cool, ill deffinetly try that, thanks. atleast im not to worried that its something big. thanks again

[Scarecrow]

I had a similiar problem. This is a long shot, but do you have extra keys on the fob? The reason why I ask is that was what my problem was. A metal on metal sound at around 5000. The key for my mailbox was on my fob and was bouncing around beneath the switch. Sounded just like engine noise...

[92 z28]

whats fob? if you are reffering to the extra keys i have attached to my bike key, then lol, i already recognize that noise. its not it

[jonesie619]

Removed the gas tank lately? Sometimes the bushings aren't set just right, and the gas tanks rattles a bit.

[92 z28]

nop, havent removed the tank ever

[ZX-2R]

e had a fella on here with no extra keys and at about 5,000 RPM or so it made a wierd noise....finally checking everything he lifted the seat and found that he had a wrench vibrating ( yes it had a Resonant Frequency) Rf at 5,000Rpm...funny how things can vibrate at only a certain freq...but it happens...

[92 z28]

i understand what you guys are saying, buut i really think its something actually tapping the bottom of the gas tank. when i get a chance next week ill see what i can find.