PRIMARY DRIVE WHINE

I had my GT550L bottom end re-built by a reputable UK builder (although I was not entirely satisfied with their service). When I re-started it after fitting it runs fine but now has a noticeable whine which was not present prior to stripdown. The whine rises and falls in pitch with the engine speed, whether in neutral or in gear. It is not related to the clutch being in or out, either. Sounds to me like primary drive gears not meshing correctly. has anyone else experienced this and can I correct it without stripping the whole motor?

I doubt you can fix it without a strip.

Sound very much like either a thrust washer has been left out or a bearing has not been replaced correctly.

I rebuilt a 380 with a missing thrust washer, it made whining noise but only in one gear.