Whirring noise

[Didj]

My '99 600 engined '95 kat has started making a whirring noise. Recently replaced chain set, but been over all the checks with regards that; tension is fine, alignment looks straight & chain is well oiled. Noise only occurs on load/acceleration; can't hear it when the bike is running stood on the stand throughout all gears. Engine has done 23k, the last 3 by myself. Gear changes are generally all fine, no popping out of gear, although I've very rarely hit a false neutral between 4th/5th. Any pointers to where to start looking much appreciated.
Dave.

[diavolo]

Double check the alignment of the chain - do not rely on the swingarm marks - they are close but not accurate. Measure from the center of the front pivot to the center of the axle on both sides.

[scottynoface]

Your chain is too tight.

[arsenic]

Your chain is too tight.

+1

[hardlydangerous]

if your using aftermarket sprockets its likely the new front sprocket.

the OEM sprocket has rubber dampeners on each side that reduce noise and vibrations

[Didj]

Chain definitely not too tight, if anything it's a little slack; I re-adjusted it on the slack side already to eliminate that possibility. Yes, using aftermarket sprockets, although the last set were the same. Will double check alignment & post back.
Thanks fellas.

[mammut89]

this method is accurate:

http://www.motorcyclistonline.com/howto/string_align_motorcycle_wheels/index.html

[Didj]

Not been using the bike, so this has been on hold, but got round to checking the alignment properly & everything checks out. Tried string method, looked along chain from the back, measured pivot to axle both sides; all fine. Chain has correct slack; I've run it near the point of chain slap to ensure it's not that before adjusting back again. Will look to check on the front sprocket for any freeplay, although I don't recall there being any on installation (side panel removal yet again, wahey!).
Unfortunately, I can't hear the whirring unless accelerating, so without a rolling road it's not been possible to listen around the engine with a pole to see if I can pinpoint the source. Perhaps I should fit my helmet with a stethoscope?!
Any other suggestions much appreciated!

[Wild-Bill]

Have you got a centerstand? If so, you could try running the bike in gear with the rear wheel off the ground to see if you can isolate the noise.

[Didj]

Yes, also tried that & can't hear the noise right up to top gear! Wondering if I can somehow create a makeshift rolling road & apply some resistance to the back wheel?? Will check the front sprocket first though...
Cheers to all for the input.

[Wild-Bill]

Possible you've got a broken belt in the rear tire. Any bulges on it?

[Didj]

Rear tyre has been replaced since the noise appeared - eliminates that possibility.
Now checked front sprocket & nothing appears loose. Additionally, went for a ride the other day & felt a hell of a lot of heat from the engine. Could the whirring possibly be a bearing somewhere in the engine; oil pump etc.? Where do I start with that?!! !

[turboboxer6spd]

Hi, I'm having the same issue. My noise I can hear if the bike is in neutral and i spin the wheel on a center stand or if I hit the kill switch and coast the bike with the clutch in. It's coming from the front sprocket. If I remove the chain I can still hear it when I spin the crank sprocket and this worries me. Not sure if its in the transmission or the sprocket bearing. With the clutch assembly removed I can see a bearing on the clutch cover side, but only a seal on the crank sprocket side. (I am viewing the crank side from the outside so this would make sense but I'm wondering if there is a bearing behind that seal)

Related symptoms? The bike has what I would consider a wicked vibration on coast or deceleration after 5k rpm. Acceleration is fine up to 9k ( I haven't tried past that) but as soon as I let off the throttle I have a bad vibration but I push in the clutch and its gone. My chain might be too tight and my alignment maybe off. Going to recheck these. After all it didn't do it before I adjusted the chain and I forgot about that b/c I painted the fairings and tank and the same time...

HOPE THIS HELPS! Anyone that could further help me would be greatly appreciated and if anyone thinks I've done bearing damage please let me know. I was going to replace the clutch frictions and steels but everything measures fine. Not sure but the color looks like it may have gotten hot before.