YZ Cam Swap - Won't Start

I put a YZ 450 exhaust cam in my WR 450.

Now the bike won't start.

When I was disassembling, I lined the crank up on the "H" mark, and the cam marks were pretty close to the top of the head. When I went to reassemble, I found the "I" mark, and timed the cams to it, the way the manual shows. The manual also shows 14 chain pins between the upper cam marks, but I have 13 with the YZ cam. :cry:

I have the YZ cam in my '01 WR426, and it needs 14 pins between the punch marks.

I think your timing is off.

Sorry dude.


Well, I had 14 pins the first time, but the intake cam mark was below the top of the head when the exhaust mark was even. It wouldn't start then either. :cry:


Check out this thread. It has pictures of the cams, from both sides. This is how it should look.

Keep working, as the end result is WELL WORTH THE EFFORT!



Tried it again. Didn't look right. Mark on exhaust cam is one tooth below top of head, but 14 pins between top marks.

It started though. :cry:

Thanks for your reply, Brandon. I saw that thread when I did a search a coupla days ago, but I thought maybe the 450 was different.

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