XBR whining

[guest1405]

Hi. My XBR has started whining while I am riding it but it fades away soon after the revs are dropped. If I nurse it along it doesn't whine but as soon as I rev beyond say 4k it starts again. If I stop, put it on the centrestand, put it in gear and take it up to revs, it doesn't do it. The noise is definitely in the engine/gearbox, not the cycle parts. Anyone had a similar problem?

[johnr]

how tight is your chain? when you sit the bike on the stand, the chain is slacker cos the swingarm is uncompressed. over tightening the chain will stress both the chain and the cush drive bearing in the back sprocket carrier. more importantly though, it will put a heavy axial load on the output shaft and its bearing behind the sprocket. id be tempted to carefully adjust the chain and try it again.

[pete]

Had a similar problem. Mine used to whine over 4k, but only when the wife was on the back. 1up no problems...
Not much help i know then nor was she...

[guest1405]

Thanks for comments. The chain was a bit slack if anything, anyway the whine sometimes continues for a moment even after stopping the bike and getting into neutral. I have a suspicion its in the clutch although operating the lever has no effect - wonder if it could be the thrust washer. I had a Hillman Imp in my youth which had a similar problem and it turned out to be the clutch thrust bearing. One other thought, having only just aquired the bike it occured to me that the previous owner might have overfilled it with oil. He had. There was about half a litre too much in there, but I cant think that would make it whine. Any other thoughts gratefully received, I will keep you posted.

[guest295]

Ooh, check the air filter! Overfilling with oil makes the excess blow into the filter, which, being paper, then becomes impervious to air. Vacuum sucks a hole into into it which makes noise.

[guest1405]

Thanks, I'll try that tomorrow although I think its more of a mechanical whine than the sound of air being drawn through a clogged filter. I've had the clutch apart today and all is well there. I am planning to get the flywheel off tomorrow - if I can borrow a puller- and check the starter clutch.

[SteveC#222]

There have been a few problems in the past with XBR starter clutches.