Strange whirring sound?

[ne-oublie]

Comeing home last night from work,i started to hear a whirring sound from the engine,i stopped but could not determain the source.By the time i got home it was worse,so when i got up today i started to investigate the noise,i couldn't feel anything anywhere specific,from the best i could tell it appears to be comeing from the cam chain area at the back of the motor.Before i start pulling things appart,what would be your best guess as to the problem?The top end of the motor was supposed to have been rebuilt,when i got the bike,it has ran great untill now.The motor is a 1000cc 1982 katana, same as gs1000, i believe.Your sugestions and addvice would be greatly appriciated,thanks.

[The CyberPoet]

Could be the generator going out (bearings worn, shaft now slightly off-center)... Without hearing it, it's something that is increadibly hard to diagnose.

Cheers
=-= The CyberPoet

[ne-oublie]

Thanks Cyber,i took the valve cover off today and checked the cam, chain cam and valve train also, all looked fine.The starter motor bearings are fine,i took off the left cover,to inspect the generator etc all looks good.I know it is hard to diagnose a sound when you can't hear it,but this is so strange,i really thought it would have been the cam chain.The noise gets worse as the rpm's increase,i can't feel anything,no other noises,just this whurring.It dosen't make any different whurring whether rideing or stationary.I will dig deeper tomorrow,thanks again.

[The CyberPoet]

My advice is to beg, borrow or steal a doctor's stethascope or a mechanics' stethascope and track it down. Literally, there are dozens of things it could be. I'd also suggest removing all the fairings and leaving them off while you try to diagnose it. But is certainly sounds like a bad bearing/race/shaft-off center -- the only real question is which one...

Cheers
=-= The CyberPoet

[ne-oublie]

I used the old wood pole trick to locate the "whurring",but had little success,i will get a stethascope tomorrow,i am a first responder,so i have one in my bag at work,Thanks hopefully this will help,but as you said "which one".

[ne-oublie]

This is getting really frustrating ,the noise is not the cam chain,valve train,generator,starter motor,clutch,i hate to think it may be a crank bearing?While tring to find the 'noise', i discovered that the drive sprocket was very,very loose ,so i tightened it to specks and thought that it may have in some way caused the 'whurring',but it did not change anything .If anyone has a sugestion as to the possible cause,let me know ,thanks.

[armor_dan]

this may be an idiotic response, but it may have some value. As my chain finally started to really bite the dust, it made funny noises, including a reverberating whirring noise. It was explained that a few of the seized links may have been causing the noise disturbance. Since i have replace the chain, the whirring in my bike has disappeared. so has the hard shifting and general turning instability in the bike as well.

[ne-oublie]

Are you talking about the cam chain? thanks.

[CorpZ]

I'm pretty sure armor_dan is talking about the drive chain

[SweetLou]

Well, it wasn't anything on the top end. We thought maybe the starter clutch was reaming engaged, so we took out the gear, and push started it, but still made the noise.

It almost sounds like a Cars Power Steering pump, right when it starts to get low on fluid, and makes the squeeling noise.

[The CyberPoet]

Well, it wasn't anything on the top end. We thought maybe the starter clutch was reaming engaged, so we took out the gear, and push started it, but still made the noise.

It almost sounds like a Cars Power Steering pump, right when it starts to get low on fluid, and makes the squeeling noise.

Oil pump? Or perhaps the oil pressure regulator mis-seated...

Cheers
=-= The CyberPoet

[SweetLou]

My next guess was the oil pump. I think he was gona take it home and check it out. The sound also accelerates with the engine.