YZ426 Cam installation

I've searched but can't find the info I'm looking for. Could someone please tell me what marks to line up horizontally and how many pins between the vertical marks. Also, this is a dumb question, but where is the timing hole to see the TDC mark, what is the mark on?


Two very important questions that need to be asked are, do you have a manual, and what kind of cam are you installing?

To download a manual, use this link:


If the cam is a stock one, or an aftermarket cam made for a 426, time the cams as shown in the manual. If you are using the exhaust cam from a YZ450 to do the DCM upgrade, it's different. In that case, time the intake cam by the book first, then position the exhaust cam with one mark at 9:00 o'clock, and the other at 12:00, and count 14 pins between the 12:00 marks on the two cams. DO NOT time a stock or aftermarket 426 cam by this method, only when using the 450 cam in a 426.


Visit the Common Threads sticky at the top of the index. All this info and more is there.

I didnt see anything in that post about the alignment of the stock cams.

THANKS! I didn't know I could d/l that manual, I lost mine. That's all I needed.

Thanks again

If you are using stock cams, you will find the info you need in the manual you get at the first link I posted.

The TDC mark is under the two timing plugs on the ignition cover. Each stock cam is marked with an I and an E. The I mark is placed at 3:00 o'clock and aligned with the upper gasket surface of the head for the intake cam, and the E is placed at 9:00 and aligned with the head for the exhaust cam. Pins are not counted with stock timing. the only thing that will tell you is whether the cams are positioned correctly relative to each other, not where they are to the crank, which is the only thing that matters.

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