Engine Noise Troubleshooting Help

[ebbed]

Hi All,

I've recently completed the build of an RZV500R from spare parts and the bike is running like a dream. Carbs are perfectly set up and balanced.

There is a weird problem though. A noise develops at high revs and then only goes away again after the bike has nearly come to a standstill. Although the noise is triggered at high revs, it is NOT correlated with engine speed or bike speed, which makes it damn hard to troubleshoot.

Looking for any good ideas to solve this tricky one!

Regards,
ebbed

[rz500guytexas]

That is a tough one. I am sure you have tried to hear what side it is. Process of elimination unfortunately. If you did not disassemble the tranny that should be eliminated. I would start on the easy side and think water pump impeller or clutch. Water pump easy to check except for possibly developing a leak at the header. Look for wear spots. Make sure all the shims and clips are installed and in proper order. Drain the oil and look for unusual metal bits before pulling the cover. You used spare parts so it could be anything. And are you sure it is the engine.

[ebbed]

Thanks rz500guytexas
BTW, I stayed in the Woodlands in Houston for 18 months..
The noise is best described as a high-pitched screening sound (I suspect mechanical). The fact that it is triggered by high revs but then not affected by revs coming down, indicates to me that it is not the clutch (clutch activated or not) or the water pump. Ditto for the gearbox. So I'm not sure what else mechanical it could be!

[lost1750GTV]

Tinnitus

[Jeff B]

If the tranny oil pump wasn't working would it cause noise? I would think that at slow speeds there is enough oil where it needs to be without the pump. Does the noise change if the clutch is engaged\disengaged, the bike moving or not? Answering this question helps identify if it's caused by the engine or tranny.

[rz500guytexas]

I live in the Woodlands proper. Unrestricted on the edge. I was thinking water pump as it spins faster it could push the impeller out against the housing and then come back in. There is a flat washer under the the circlip that keeps it in place. Hate to ask if you pulled the plugs and checked for piston debris. There are so many spacer and thrust washers on the the clutch side that any one could be in wrong spot or clutch hub not tight enough. I would think water pump rev it up with a long metal dowel on the housing or screwdriver and listen to it like a stethoscope. Engine wise drain the oil and filter it through a paper towel and look for excess debris. Worse case scenario is tranny or some gear and it locks up and you are going down the road separated from your bike. Seizure is one of my fears on track and a catastrophic tranny lock up is my nightmare. A few allens and the body work is off and if the oil is good put it back in. If you have eliminated brakes and wheel bearings keep us updated.

[ebbed]

Thanks all for comments. I aim to take a video/audio recording of the noise tomorrow and post with a link to YouTube for further comments/suggestions

[ebbed]

Update: passenger arranged to record the noise and, as Murphy would have it, no more noise..

[rz500guytexas]

I would still check oil for unusual debris. Again a tranny failure is pretty dangerous. Do you want to ride with that in the back of your mind every time you throw a leg over the bike. Road riding is dangerous enough. I hope I put that thought in your head. We are all here for one another, please do not take it wrong.

[johnnyrotten13]

hi all reading this made me join the forum i too seem to be having the same problem a strange noise when i rev the bike hard but its intermittent so im assuming its not crank related as the noise goes at lower revs or whilst ticking over??