2005 YZ125 question

The only way to know if the stomper lever was replaced is to look. Pull off the cover and look in the bottom right hand side. It is not something you could hear because it is not spining the hole time. If the stomper bearing goes bad, it will spill its bearings into the bottom end. The new stomper lever does not have bearings but rather a bushing (without balls.) I have a 05 125 and can hear a noise coming from the clutch side. With the engine running, pull in the cluch. Does it go away? I did a lot of research on this, because I heard it only after my to end was done. I was really paying attension and think that is why I never heard it before. From my research, if it is the same noise, it is normal. Have fun with the yz125, it is a great bike.

Some whine is normal because of the cut of the gear teeth on the primary reduction gears between the crankshaft and clutch basket. It should be about the same on all bikes so if you have a chance, listen to another 2-stroke. The Yamahas do seem to be slightly louder, though. If you think something is wrong, don't be affraid to try to chase it down. Having bearing bits floating around in your engine can cost a lot of money.

Pull the cover off and look at it. If the bearings themselves are gone, you have to worry about the tranny, not the main bearings. The ball bearings in the stomper lever are too big to get into main bearings but are hard enough to trash your entire tranny.