Topic: 4th and 5th gear whine

[taxiscooter]

I have a cb750k7 that runs great, but seems to have a lot of gear noise and whine in 4th and 5th. It lessens with less torque, but whines with acceleration. Almost sounds like a pinion noise.  Is there a cure, or is this normal? Shifts flawlessly and doesn't jump out of gear.  Thanks

[BobbyR]

I have a 78 and it has been whining like that on light acceleration mostly. We have other threads on the same group of noises these things make. Since you say it shifts fine, maybe leave well enough alone. You may want to check your timing chain adjustment.

[jtb]

Ditto my 77 750F

[KingCustomCycles.com]

Rear wheel bearings only whine under load when they are about to give up the good fight.  Probably easier to hear when the revs drop or louder when the wheel is turning faster.  Put her on the center stand and give the rear wheel a jiggle.  While she is up, check your swing arm play and chain rotation.  All should be smooth and tight. 

[taxiscooter]

Thanks for the suggestions. Would also add that I can pull the clutch in going at highway speeds and the noise goes away instantly. Swingarm is tight, all sprockets are new(1000 miles) and has a new 630 o ring chain. Wheel has just been trued and all spokes torqued within last 1000 miles. New bearings and brake shoes on the rear also. At speeds near 60 mph it seems to be less noticeable.  Thanks.