Wolf 49cc 4t 139qmb short case

[moose88]

Hi guys new to forums so I apologize for any dumb mistakes I make. I will do my best to learn from each one lol.

My wife's wolf rx50 139qmb short case started making a helicopter blade type noise when she reaches almost top speed coming from the cvt, this week it sounded like a bearing when it is spun to fast. I pulled the cvt cover belt clutch drive face and variator out last night and all that looked to be in good shape and had no run out on any rotating surface. I will be tearing down her gearbox tonight but was hoping someone hasran into this issue before. It's always nice to hear that someone had the same issue as you and what they did to correct it.

Thanks guys and gals!!!

[geoffh]

Sorry you seem to have been missed in the melee,welcome to the forum have you sorted this?

Geoff

[90GTVert]

I've had bearings going bad in the gearbox cause a vibration and noise. It would change frequency or disappear as speed changed.

[GrumpyUnk]

Have you checked the lube level in the final drive gearbox? Spun the clutch bell with the belt removed? Compressed and released the torque spring?
You can feel the smoothness of the gears and possibly the bearings in the final drive. Draining the 90w and catching it for examination would show if there is glitter from things self-destructing. If you spun the clutch, you are turning the input shaft to the gearbox directly, and rough bearings should give a little feedback. You can turn the rear wheel, and the input shaft should spin at a good clip so you can hear the function w/o needing to block engine noise.
You can also get some 'different' noises if the clutch friction arms have broken and are not held in position properly. They may still work, but their lifetime is likely shorter than normal. Remove the clutch bell(hold by using the rear brake), and examine for damage. It can happen for no particular reason it seems. Springs can also break leaving bits and pieces to get ground into other parts.
tom