Recently I broke the 4th gear driven in my tranny, as well as just one tooth on the 1st gear driven, and the main shift fork too. I replaced the broken parts and rebuilt everything back to specs, as per the service manual. It started right up, but now there is this weird humming/ whining noise coming from the bottom end, and it will only go away, only a little, when I pull the clutch in. But the sound isn't the main problem. I cant seem to get it to shift into third gear at all, but first, second, and neutral are super smooth. I'm at a little lost as to what could be causing the problems, any and all help is appreciated.

 

If you didn't replace all the shift forks,could be one that's having problems,a bad spot on the shift drum or even the shift indent may be stopping you.Whining that goes away when you pull the clutch lever is telling you something. I'd recheck the clutch assy. Lot of parts in this engine,over 8 internal bearings,3 shift forks,plus the clutch assy.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse