# Need 4 stroke help...yz426/yz450f **URL:** \ **Category:** Shift518 Automotive\ **Created:** [January 9, 2011, 6:57pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348 "2011-01-09T18:57:23Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![SSmokinn\_SS](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@SSmokinn\_SS](https://forums.speedlife.net/u/SSmokinn_SS)\ **Post date:** [January 9, 2011, 6:57pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348/1 "2011-01-09T18:57:23Z")
I will be the first to admit, Im new to the 4 stroke world. I have owned 2 strokes all my life, and I never wanted to own a 4 stroke, until I needed too a few years ago. Long story short, I have never had one open. now, My quad is a aftermarket Honda chassis, with a yz426f motor with a Athena 444 big bore. I have the motor out of my quad, sitting on the bench to finally replace my 5th gear shift fork I bent 3 years ago, and here is where I get confused… I know the top ends on the wr400/yz426/yfz450 are all interchangeable. My motor, being a 02, I am not sure if the shift forks/transmission gears are year specific. Basically, Im wondering if 01 yz426f shift forks, will work in a 02 motor? everywhere I look, it just says 01. I also am aware that there are a few years that the yz450f dirtbike motor was a 4 spd. I wouldnt mind making my 426f based motor a 4 speed. It has the power to pull it, and my gears would be longer…Can I do this? ---
**Author:** ![88slowmarro](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/88slowmarro/32/6339_2.png) [@88slowmarro](https://forums.speedlife.net/u/88slowmarro)\ **Post date:** [January 9, 2011, 7:09pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348/2 "2011-01-09T19:09:30Z")
i know on mine the trans was all diff as i sheared my forks once . and it was a 01 426 . the only changes i made was using a 450 exh cam on it . if i remeber right most of the diff was in the case where the shafts set it and so on ---
**Author:** ![SSmokinn\_SS](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@SSmokinn\_SS](https://forums.speedlife.net/u/SSmokinn_SS)\ **Post date:** [January 9, 2011, 7:17pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348/3 "2011-01-09T19:17:33Z")
> [@Hello From Clearwater](https://forums.speedlife.net/t/hello-from-clearwater/38599/22): > > i know on mine the trans was all diff as i sheared my forks once . and it was a 01 426 . the only changes i made was using a 450 exh cam on it . if i remeber right most of the diff was in the case where the shafts set it and so on I know that the 01 transmissions had problems, and were weaker then the 02’s. I am just wondering if they use the same exact shift forks. I only need the 5th gear shift fork, as my 1-4 shift flawless. I made a post on exriders. I am really curious on switching to a 4 speed. ---
**Author:** ![88slowmarro](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/88slowmarro/32/6339_2.png) [@88slowmarro](https://forums.speedlife.net/u/88slowmarro)\ **Post date:** [January 9, 2011, 7:23pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348/4 "2011-01-09T19:23:13Z")
ya may need to do the whole lower , like i said the cases are diff between yrs . just get the hardened shit i did and i never had a prob again . ill try and remember where i got my shit thru . it wasnt exp and had it all quick ---
**Author:** ![SSmokinn\_SS](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@SSmokinn\_SS](https://forums.speedlife.net/u/SSmokinn_SS)\ **Post date:** [January 9, 2011, 7:43pm UTC](https://forums.speedlife.net/t/need-4-stroke-help-yz426-yz450f/256348/5 "2011-01-09T19:43:32Z")
> [@Hello From Clearwater](https://forums.speedlife.net/t/hello-from-clearwater/38599/24): > > ya may need to do the whole lower , like i said the cases are diff between yrs . just get the hardened shit i did and i never had a prob again . ill try and remember where i got my shit thru . it wasnt exp and had it all quick Im not in a hurry to get the parts really. I still need to order swingarm bearings and a new swingarm bolt. When I went to take the motor out, my swingarm bearings where shot and fused to the bolt, so I had to cut the bolt out. Sucks thats its a $50 bolt lol