Shifting problems.....'03 YZ250

[Butta]

Ok, I've searched and read about the 125's having issues....but can't exactly pin down what has just happened to my 250 this morning.

Bike has WR 3rd through 5th gears, pretty much everything else is stock.

Riding at the track today, bike was working flawless, as usual...then, went back out after a good solid session and a few corners through the first lap I roll out of a corner and find myself in neutral...I upshift, neutral still...I concentrate to ensure a positive shift and still neutral...I shift down and find a gear. Up shift again, neutral. I pull off the track and shift up and down, finding false neutrals and sporadic gears. I ride back to the truck and investigate.

Once the bike is in gear, it doesn't pop out or do anything weird, but I can upshift until I'm tired, and keep hitting gears and neutrals....every once in awhile the gear shift lever would kind of "stick" after down shifting, too...

Through the search function on here, I've come to believe that splitting the cases is probably in order, to be on the safe side. But, it also seems like it could be the shift stopper mechanism, as well??

Any clarity would be appreciated. I've done top end rebuilds before, but never have split the cases....advice?

Thanks!!

[BDubb106]

Could be a shift stopper but dont rule out a bent shift fork... only way to know is tear it apart and inspect. Sucks but theres no other way to know for sure. Either way it will be a fairly cheap fix.

Happened to my 250 last year and the shift fork was bent slightly causing false neut. and couldnt find any gear but first. Found a set on ebay for like $20 in like "brand new" condition and replaced them all with no issues to speak of since.

[Butta]

How intimidating is splitting the cases? I can do a top end in a couple hours, taking my time.

[BDubb106]

Its very simple if you have a manual which is highly recommended if you've never torn into one.

It sounds alot worse than it actually is! I tear mine apart twice every season on all 4 of my bikes, once 1/2 way through and once again at the end of the season. I can tear it down, inspected, regreased and back together in around 4-5 hours.

[Yamaguy55]

Could be a shift stopper but dont rule out a bent shift fork... only way to know is tear it apart and inspect. Sucks but theres no other way to know for sure. Either way it will be a fairly cheap fix.

Happened to my 250 last year and the shift fork was bent slightly causing false neut. and couldnt find any gear but first. Found a set on ebay for like $20 in like "brand new" condition and replaced them all with no issues to speak of since.

I'm either for bent shift fork, or the transmission shafts/drum with too much side play. That's why it works one way, not the other.

Separating cases isn't too bad. get the proper tools and it is a breeze. And use the factory sealant, not NAPA silicone. While you're in that far, it doesn't hurt to replace seals for the crank and the transmission output shaft.

[BDubb106]

^^^ Good info Yamaguy... one more thing you might as well replace is main bearings while your in there. Im a firm believer that fresh and tight bearings will increase the life of corresponding moving parts.

[Butta]

That was my thinking, too....since it's apart, might as well replace the wear items. Hadn't thought about the trans output shaft, though. Thanks!

[Yamaguy55]

^^^ Good info Yamaguy... one more thing you might as well replace is main bearings while your in there. Im a firm believer that fresh and tight bearings will increase the life of corresponding moving parts.

Actually, it is impossible to have too fresh bearings and seals. Transmission bearings are often overlooked, and are often ok, but not always.

[BDubb106]

Actually, it is impossible to have too fresh bearings and seals. Transmission bearings are often overlooked, and are often ok, but not always.

Couldnt agree more!