2010 YZ450f tear down, valves look odd? Expert opinion?

In response to the valve discoloration: I wonder where the open end of the electrode aligns in the combustion chamber. That MIGHT cause a combustion pattern that would make one valve hotter than the other. The Easter Bunny might be real too...:thumbsup:

about the valve, it looks like the hotter valve might be due to bad sealind between the valve and seat, causing heated gasses to heat it up more?

i have more than 200 hours on my 09 yz450f and im not going to open the engine like yamaha said dont fix whats not broken unless its nearly broken

i have more than 200 hours on my 09 yz450f and im not going to open the engine like yamaha said dont fix whats not broken unless its nearly broken

I'd place a bet that in the long run Davey will spend much less on his bike than you will (or the poor sap that buys it from you)...And nothing worse than being on a long ride with the "I don't fix it until it's broke guy" when his bike breaks...

i have more than 200 hours on my 09 yz450f and im not going to open the engine like yamaha said dont fix whats not broken unless its nearly broken

I hear you completely,, I pulled 280 hours on my 02 CRF without pulling nothing but the valve cover off to do the valves. Never had a problem, and still ran as good as when I pulled it off the showroom floor in 2001 10 years later.. If it still runs now with the new owner, is a different question.. My maint. was done at every ride since I bought it,

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now