03 450 HELP!

Hey guys, I'm getting my 450 ready to sell. I noticed that the timing was way off when I took the valve cover off. So I timed it, piston at TDC, and then adjusted the valves. I got them in spec. Put it all back together, noticed that it had way more compression, but it wont start. Help

Anybody? It seems like it sounds different when I kick it over. Won't start. Anything guys?

The two variables you changed were timing and valve clearance. If timing is off it won't start. If valve clearance is too tight it won't run/hard to start.

Recheck those first

The two variables you changed were timing and valve clearance. If timing is off it won't start. If valve clearance is too tight it won't run/hard to start.

Recheck those first

yeah I set the timing and the clearances at top dead center on the flywheel, timed it, now I put it to TDC and check it, and the timing is WAY off. It sounded different when I started it. Going Tuesday to get some shims.

So the exhaust valves measured .27 mm and the intakes at .14 mm. Set the timing according to TDC on flywheel. Still won't start. Has visible spark, compression, air/fuel,( the plug was wet ), has timing, what am I missing?

I know the exhaust valves are a little more than the clearance but is it that causing it to not start? It also back fires about every 10th kick.

My friend and I got the timing wrong by a little once, it was on his 03 crf450r. It wouldn't start. I think you have the same issue. Make sure your cam chain and cams are where they should be. One tooth difference and their is no way the bike will run.

My friend and I got the timing wrong by a little once, it was on his 03 crf450r. It wouldn't start. I think you have the same issue. Make sure your cam chain and cams are where they should be. One tooth difference and their is no way the bike will run.

I got it as close as I could. It was almost perfect. If you go one tooth up, it's too far, one tooth back it's just a little under the case.

Well that means your timing chain is super stretched, order an oem one pronto. They are like 25 bucks on rockymountainatv.com in there oem section.

Well that means your timing chain is super stretched, order an oem one pronto. They are like 25 bucks on rockymountainatv.com in there oem section.

will that make it not run? All I'm trying to do is make it run for the guy that wants to trade his yz 250 2006 :)

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