My 2001 Yz426 wont run right, please help

They're model specific to a large extent. Actually "engine family" specific. YZ/WR400/426 can be interchanged as whole or partial sets to some degree. The '03-'05 YZ450 is a 4 speed, but can be swapped with '03-'06 WR450's as a complete transmission, including forks and cam. Later 450's can be swapped or partly mixed, but that won't help you.

I thought about the 450 being a 4 speed not long after I posted that, and felt a bit stupid for asking. I'm planning on tearing it down this weekend and assessing the damage. Thanks for all the help

I just replaced 4th gear and 2nd on my 2000 yz426f...the best price I found was at "Cheap Cycle Parts" online. They delivered fast and have a diagram that's easy to find the exact parts you need. I think I paid under $70 for the 2 gears. hope that helps you out.

Well, it's been quite a while since I've been on. With working, finishing school, and trying to start a career life has been crazy. You guys were right, the dogs on 3rd, 4th, and 5th were all rounding off and causing my problem. It seems to me that the dog-to-dog design between 3rd and 4th gears is a weak design.

Replaced all three along with the shift fork and now she shreds like shes brand new.

Thanks for all the help.


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