04 yz450 won't start. What am I missing?

my buddy's 04 yz450 won't start. Put a new head and piston and rings on it. It started n ran but had a ticking/knock, sounded like from the top end. Checked the timing and it might have been a tooth off. Changed that and put it back together. Now it won't start at all, only tried kicking it.

I would check timing again first. Also is there compression after reassembly? If not or low check for a bent valve (cup stuck partially down)

I would check timing again first. Also is there compression after reassembly? If not or low check for a bent valve (cup stuck partially down)

It has compression (I didn't measure it with a tester) but feels the same as before when kicking. I will check the timing again and check for bent valves after work.

Edited by bikridr69

The easiest way to find a bent valve is excessive clearance. 

If it has normal compression, why would you suspect bent valves?

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