2001 WR450 valve check

I am going to check a buddies valves for him tomorrow. He has never done it, s I am guessing it will need to be shimmed, maybe...

Im sure these are the standard 450 shims. My main question is, is there anything i should look out for or check at the same time I have the valve cover off?

If he's got a 2001, it ain't a 450, it's a 426. So whether the shims are the same, I don't know :thumbsup:. Just look for anything out of the ordinary on the cams, the seats and the cam caps. Also check the cam chain and teeth for wear...SC

He keeps telling me its a 450... Ill know for sure what it is when I get the book and start tearing it down tomorrow.

Is there any service I should do to the tensioner? Ill check the book...


450's didn't show until '03...he's got at least a couple of his digits out of whack :thumbsup: ...SC

Its a 2001 WR426. OMG, what a pain in the ass to do a lash check. Had to pull top motor mount off to get valve cover off. One intake and both exhausts are tight. OMG what a bigger pain, the carb has to come off to get the cam chan tensioner out, so you can pull the cam journals off. Ouch... I really appreciate how easy my MX bike is to get at all of this stuff now.

Anybody know if the 01 426 uses the same diamter shims as the 450s?

I tore the 426 down, plus did a valve adjustment and oil change on a 2005 Yamaha V-Star 1100. The entire exhaust has to come off of that to change the filter, and almost everything on the top of the bike has to come off to adjust the valves. What a bogus day in the garage...

I believe that the shims for the 400,426,450 are all the same. Also yamaha, honda, suzuki are the same for 450s. I don't know about the new kawi 450. The 250f of all makes are smaller diameter than 450s. :thumbsup:

You should not have to pull the carb for cam tensioner. After you do the valve check a couple times it is a piece of cake. I can have the bike apart-check valves-back together in a casual 45 minutes now. Buy a inch-pounds torque wrench for cam caps, some in this forum have found out the hard way that overtorquing caps can be $$$.

I got it all back together for him and it runs great. Put a new plug in it for him too.

The carb had to be loosened and kind of twisted to get the tentioner out.

The biggest gotcha: The cam bearing retaining clips are very easy to drop into the motor when you new working on this motor... When you pull the caps up they just fall out. If anything falls in the opening between the left side intake and exhaust, its a straight shot down and out into the timing chain cavity. I had to fish BOTH clips out of the timing chain hole! One fished out twice. They are tricky to get in right. Now I know ALWAYS be careful of these things.

I have an inch pound torque wrench but it doesnt go down to 7 ft lbs... I did just guess, but I have pretty good feel for it. I didnt make them to tight or to loose. Hopefully.

The spark plug was a few months from being a permanent part of the head though. NEVER leave a plug in for 3 years without checking it!!!!!

Thanks for the help.

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