07 valves sticking?

I agree on that it depends on the dealer sometimes they can find some how to warranty they need to be tactfull on the claim. One thing to think about is kibblewhite valves are good alternative to stock and are more economical. I used stock oem because I did not want to wait for parts. Also my guides were fine. rember though different valves require different keepers etc. I do feel your pain these thumpers are not cheap to do I had 200.00 into mine and it was just the exhaust valves. Good luck.:worthy:

They drove 2 hours to pick your bike up?....Wow, thats good customer service. But, I don't trust dealers, I'd make the trip.

Tell them to save the parts FOR SURE if you cannot get up there to see it.

One thing to think about is kibblewhite valves are good alternative to stock and are more economical.
The valves are a little less expensive, but they require the matching spring set (because they weigh twice as much), which includes titanium retainers, and goes for over $200. By the time the smoke clears, you won't save much, and they aren't any more reliable than Yamaha OEM.

Here is some pics of the valves.

DSC00165.jpg

DSC00163.jpg

DSC00162.jpg

Here is the head after they cleaned it.

DSC00166.jpg

Interesting. I wonder why the springs broke?...

The exhaust valve seats look corroded. Maybe its a shadow on the picture of something....

Interesting. I wonder why the springs broke?...

The exhaust valve seats look corroded. Maybe its a shadow on the picture of something....

Thats a shadow or something. They are really clean.

Both springs broken in the same place, near the end of the coil. Springs assembled too short would be my guess, but who knows why?

i guess i will retract my full of it line if those are the springs. both broke same spot??? that my friend should be a real possible warranty if pushed

They are saying its over rev or its from where the valve's was sticking in the guides.

i was wrong before but i have reved mine to the moon squeezing a little more. the rev i don't agree with maybe just bad springs.

They are saying its over rev or its from where the valve's was sticking in the guides.
Valves sticking in the guides won't cause that. Only three things will, and all for the same reason.

It looks like the springs were coil bound (bottomed out, so to speak), which they would have done only if the valves floated, which should be impossible with a rev limiter, or the springs did not have enough installed height, and bound when fully compressed.

But there is a third possibility, and that is that you over revved it mechanically by down shifting too far too soon. The rev limiter can't protect against that.

I don't think its over rev. I don't remember down shifting and cause it to over rev. I have rode my 05 yz450f with over 100 hours and never had a drop of trouble with the valves. Never even had to adjust them. Hopefully it won't do this all over again.

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