Shift problems YZ125

[JIM77]

Not a VMX, but my sons 2009.

It won't shift sometimes under load into 5th and 6th. I've pulled the side off and clutch out, gone through all gears and it seems to hang up between 5,6 sometimes and takes a bit of manipulation to get into gear.

Before I pull the shift pawl, stopper and drum out, has anyone got any thoughts, what to look for?

I can see into the box and there is no signs of wear.

[Lozza]

shift drum or shim out of place

[rocketfrog]

The shift forks cannot tolerate much wear and are prone to damage if they are allowed to ride contacting the thrust face of the cluster/ gear grooves. Look for bending or bluish discolouration of the fork tips. The shift cam assembley is very robust and I doubt there would be breakage there, but you never know. The fact that it is only 5th and top makes me think that the selector fork and matching gear have excessive wear.

[JIM77]

So what your saying, is I'm likely going to have to split the cases.

I had another look last night and it will hang up a little in the lower gears.

Before I go the route of splitting cases, I'm going to try giving the shift pawl a clean and the shift stopper. If I can get it to shift a little easier, I'll replace the stopper and give it a test ride.

Apparently the 05-06 models had a known problem with their shift stoppers, causing the same symptoms, except eventually the roller would shit themselves totally.

[rocketfrog]

Then definitely inspect all the parts in the outer case for wear and correct fitment (I had assumed that you would have checked what you could access without going the split).

Please let us know what the outcome is regardless.