gear box problems?

[steve426f]

I have a 2000 426 that has a problem. in fifth it acts like the gear is missing teeth first through fourth are fine and i can run in fith but when i go full throtle it jumps all over not like a limiter but like its missing teeth but at lower rpm smooth as ever anybody know what it could be or more importantly how to fix??

[darksun27]

yes i know exactly what it is. its your shift fork. mine done that a month ago but 2nd instead of 5th. you will think the teeth are stripped out but it is either a bent or broken shift fork. and trust me, to save u alot of time replace the gears along with it. i am going through the 2nd phase of replacing my fork because i didnt.

[im_slo_on_my_sm]

Exactly right, my shift fork is bust along with several of my mates.

It goes together with clutchless shifting and is a known problem on the rubbish yamaha gearboxes.

Rebuild with the gears or rebuild again after a few more rides.

[grayracer513]

The shift fork is either the cause of, or has been damaged by, worn locking dogs on the fifth gear and the gear that locks it to the shaft (third, as I recall without looking it up). Replacing only the fork will not cure your problem.

[darksun27]

just got back from yamaha today with my shifter fork problem. the dogs on the 2nd and 4th wheel gear were worn badly. look for rounded off edges. this will cause the gear to not lock tight and act like a incline and slide right apart causing your fork to bend or break. overall it cost me around $200 to replace both gears and the fork

[Pincushion]

$200 might get you the parts, but that couldn't possibly cover labor too. It's a pretty big job.

Classic example of Bad Dogs!!

[darksun27]

$200 might get you the parts, but that couldn't possibly cover labor too. It's a pretty big job.

Classic example of Bad Dogs!!

yeah i know, i do all the work myself and btw thats exactly what mine looked like

[steve426f]

so if you have never torn into the gears on a moto would this be a good place to get some experience or is it alot of specialized tools and super complicated1 i just had the top end rebuilt and i don't want to drop that much green again if i can do it myself