Will it fit?

[509Rider]

Hey guys,

New to both the forum and my 02 426, so go easy on me. Found out that my slipping 5th gear wasnt the clutch, but the shift forks so I'll need to replace them. There is a guy parting out an 02 yz 250 two stroke for cheap, and i was wondering if the shift forks are the same. I was looking on ebay, and they look very similar for both bikes so I thought you guys would know if they are the same. Thanks

[RiderX]

They're the same.

[grayracer513]

They're the same.

Not quite, they aren't. Shift fork 3 is different. For 5th gear you need fork #2, which is the same.

The real problem is not the fork, however. Sure, the fork will have been damaged, but the trouble lies with the 5th and 3rd pinion gears (on the main shaft), and the 3rd pinion from a YZ250 is a different part. It should drop in and work, but I don't know if it's strong enough for a YZ426.

[RiderX]

Not quite, they aren't. Shift fork 3 is different. For 5th gear you need fork #2, which is the same.

Oops, you're right. I looked up the part #'s and thought they were the same. They prefix is different on Shift fork 3. My bad.

[509Rider]

K, so i'll probably have to get a new shift fork and 5th pinion gear, but if i just don't use fifth how long could i safely go? The slipping isn't that bad and it only happens when I'm almost at top speed. I just really, really don't want to tear the engine apart on a bike that runes so well just yet lol.

[BBrown626]

It won't hurt to keep riding it if you avoid that gear.

Don't miss the point though that the mating pinion is bad too. Read Gray's post again.

It isn't really the gear mesh that is bad, it is the cogs on the side of the gear that are failing you. Don't forget you will want to replace all your bottom end bearings and possibly the crankshaft while you have it apart if you haven't replaced them before and the bike has a lot of hours on it. If you aren't doing the work yourself you will save a lot of $$$ by doing it all at once. If you are doing the work yourself you will be saving yourself a lot of emotional pain and suffering that would occur if you have to go back in there a short time later because a bearing failed. Good luck either way.

[grayracer513]

K, so i'll probably have to get a new shift fork and 5th pinion gear, ...

5th AND 3rd pinions.

[niles]

You're better off just to buy new then you know you are getting good pieces.

[509Rider]

5th AND 3rd pinions.

Got it bud.

[cowboyona426]

Welcome from another 509 area Yamaha guy.