'03 Cam in a 2000 wr400???

Just put the '03 cam in my '02 wr250. What a beautiful thing. It messed me up at first though; I kept reaching for that damn release lever. Starts on the first or second kick every time.

Of course I must now have it on my '00 wr400 that is set up for Dual Sport. My mechanic at my dealer says it wont work, but I thought I read a post here that said it would.

Is there any aftermarket companies working on these cams as well?

Just looking for a definitive.



someone installed one in either a 99 or a 98.

>> So far, so fat! (that would be fat, dumb and happy)

I have the 2003 YZ 450 cam in my '98 WR400. No worries so far. I have maybe 250 miles on it since the change, 120 of those under race conditions. No problems yet.


My mechanic was pretty confident in saying that it is not possible. I'm sure if it worked on your ‘98 it should work on my 2000.

Did you have any difficulty or challenges during the install?


I had no difficulties with install. If you have done a routine valve adjustment, then you have done everything needed for the cam switch. The only pitfall that you will run up against will be the shims underneath the exhaust buckets. They will be about .15 to .20 mm too thin.

So, you will get the engine open, take off the cam chain tensioner, then remove the exhaust cam. Get the new one lined up, put the cam chain back on, put the cam chain tensioner back on, then measure underneath the new cam. Your gap will be too big, so you will then have to loosen the cam tensioner, take the new exhaust cam back out, and then take out your existing valve shims, and head to your local blue dealer. Hopefully, he will trade you across the counter.

Take your new shims home, get them under the exhaust buckets, get the new cam back up there, line it up (look at the lobes from the right side of the bike. The tops should be symmetrical) and put the cam chain and tensioner back on. After that, recheck your clearances.

Should be good to go. NOW, it is very important to cycle the engine through a couple of times. Make sure nothing is hitting or striking before you close the thing back up.

After that, you will have one of the easiest starting bikes around. Much better than stock.

Good luck, and I hope that it works out for you.


Post your impressions when done. I'd like to know what you think.

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