wr450 cam into yz426 pic

I think you need your dots straight up. Not sure with the 450 goin into the 400. But my 450 is straight up and the YZ cam was too.

you are talking about the 12 o'clock dot? i seen the post with 13 14 links but don't know how that applies to me.

I think I'm going to need stock timing for wr450...

Any one have a book they can look at an let me know.

This site was a big help when I did mine. http://homepage.mac.com/abkt/abk/PhotoAlbum43.html

The dots should NOT line up though, VERY IMPORTANT.

Also, check out the YZ cam thread on the YZ site, you should find what you need here. LOTS of info, almost too much, but spend some time and learn about this:


There is also a PDF file that Yamaben put together that explains this mod in great detail, here is the link:


This is the document I had in hand when I did the mod about a month ago and the bike ROCKS now. Dont forget to reject afterwards. :)

out- DD

I think the bigest problem is im installing a wr450 cam into my 00 yz426. i have not seen where it has been done this way.

I did read as everyone is installing the yz450 cam into a motor. i should have just got that cam but litle late for that now.

I have the same question...I'm putting a WR450 exhaust cam into my 02 WR426. Since I want to stay with WR timing, shouldn't the dots line up the same as my stock WR426 exhaust cam?

If i need 13 between points for wr timing how would i do this without back of cams looking not like pdf.

I have the same question...I'm putting a WR450 exhaust cam into my 02 WR426. Since I want to stay with WR timing, shouldn't the dots line up the same as my stock WR426 exhaust cam?

NO, they should like up like the bike the cam came from. so get the spec/manual/picture from a WR450

It is hard to tell from the first picture exactly how the decomp mechanism lines up... that is the key to the 2003 series cams... where the decomp mechanism cuts in... From the looks of the picture, you 'could' be out one tooth... but it is hard to see from the angle you have in the pic...

BTW, the factory timing dots lose meaning in this situation...


Thanks yamaha.dude

Well i decided to go ahead an finish the install an here is the problem. with the cam set the way it is in picture i have decomp working but bike will not start.

If i move i tooth either side of that point i lose decomp an bike still will not start.

I put stock cam back in an bike runs. my question is will needing a rim shim job cause it to not start?

this is what i got for reading.


.09 .10


.07 .06 .06

:) im getting real good at removing cam not getting no where with predicted & expected results :D

I was just reading a post from yz250f board an they were saying that due to the little bump-out on the cam it is going to cause a little lose in compression(decomp) an starting is going to be tuff.

Now this is making sense but is that what im going tho?

I can see how this might be the problem but not sure :)

If i had to describe it it was like kicking using the lever was ok decomp gone but if i rolled it slowly i would get to a point where it stoped from compression like a stock 426.

maybe i should just put wr450 cam back in an clean plug an try kicking it at different speeds to see if it works?

Ok i finally got the bike to run :D

After installing the chain to have 14 pins an installing shims i got it to start.I had the thing timed right at one point but when i didn't start after 3-4 kicks i stopped an played with timing :)

I just have a few question as to what is normal or not normal. how Manny kicks should it take to start? stock cam was about to maybe 3. also should it feel like it did but just not stop at TDC like stock cam did?

One last thing i had a huge brain fart :D an got 3 #155 shims when i should have got #165 how big of a deal is this going to be? i kinda want to say i here more tick tick from valves then before but may also just be Nevis about maybe doing something wrong.

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