cam degreeing

I think my cam has slipped on the sprocket. Can someone provide some data about opening and close degrees for yz426 (or yz/wr 4xx)

10x a lot!!!

I copied these down from another poster a long time ago:

YZ timing is:

Intake 113 atdc

Exhaust 101 btdc

(I assume this is at .10 inches of lift) :)

So WR Exhaust would be 112.35?? :D

You should probably send a PM to SFO or Taffy to verify this, they will know first hand what the timing is.

Hope this helps.

if you're indexing the cams it has to be done at maximum lift. if you can get to 108 degrees on both cams you'll be ok.


Do you mean separation lobe angle?



no, i'm saying that you measure the lift of the cam by measuring the actual bucket (and shim) dropping down (i.e. the valve opening) and when it is at maximum lift you will have the same reading over about 3-5d of crankshaft movement. annoying i know but it's the truth. after rolling the engine back and forward several times you will get a d(degree) that you're happy is 'it'.

you need 108d, ok?


Thanks Taffy. I got it right this time :)

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