does any one know what the comppression is for a yfz 450 mine is 135 just think it is a little low just wondering thank u

 

I don't think it is possible to check the compression on the YFZ (at least not that I am aware of).
I believe the cam has a de-compression pin which bleeds off pressure in the cylinder so that it cranks over easier prior to the bike firing up.

At 11.9:1 it has fairly high compression while running though!

Does the motor smoke? How many hours you got on it?