[tcloke90]

Hi guys looking for help on 07 crf250r after bottom end rebuild while riding changing into 4th gear it goes to neutral when i put the trans together everything spun freely on shift drum checked the shifter mechanism seems to move when gear shifter moves
Cheers tim

[JimDirt]

Welcome to the site !!

Its possible that you have some shims in the wrong place ?? , or you have the shift drum/forks installed incorrectly ?? , or they were worn and upon re-assembly the issue got worse because of a shim misplacement ?? , sometimes just 1 shim in the wrong place will offset a gear enough to cause this , especially if the gears had any kind of wear on the cogs , if they have any rounding to them the gear will not go all the way to the other and slip back and cause it to pop out of gear

Also , on the clutch side the sift actuator could be mis-aligned or bent , or the spring not seated properly , what started the issue ?? , it was shifting fine , then it just started skipping 4th ?? , or did it do it from the first after re-assembly ??

Did you by chance drop the bike on the shifter ??

Any of these things can cause your issue , if it worked fine before , then it has to be something you did during assembly

A little more detail as to what happened , like it was working fine and you were speed shifting (without the clutch) and jammed the shifter , or you fell on that side and jammed the shifter , or it did it the first time you rode after rebuild and does it every time , or just occasionally , were you riding easy (trail riding) or at the track ?? , was it on the first ride , or after several uneventful rides ??

But i am guessing the issue will be in the shift drum , or on the clutch side with the actuator , or a worn cog (the fingers that stick out of the gears)

[tcloke90]

It was on first start up after rebuild and im pretty sure none of the shims come of or moved

[JimDirt]

You could have put one on the opposite side and it moved everything over far enough to cause the issue , if it was not caused by a crash , then the only other options are a assembly mistake , or a worn shift drum or gear cog or shift actuator

[tcloke90]

Thanks mate ill pull down it on the weekend

[tcloke90]

Ia there anyway to figure out what washers go where

[JimDirt]

I would look more at worn parts than shims , as that is what i am thinking is the main issue , the shims should only be sized for each shaft so they should not be easy to mix up , but it can happen

This is a chart from the Factory Honda Service Manual ,it gives you all the service/wear limits of the transmission components



This is a list of common issues when a transmission pops out of gear



Hope that helps some