When to change piston on a 2010 yz450?

I have 97 hours on my 2010 yz 450 i change oil with full synthetic every 9 hours and keep air filter very clean bike runs perfect plenty of power. Valves are all in spec. I am starting the NMDRC harescrambles in feb do you think I should change out piston before the season? and what about the cam chain should that be replaced to??????? :lol: :lol: :bonk: :bonk: :lol: :lol: :lol::smirk:

Look in service manual

Look in service manual

What will that tell you?

According to that, the piston needs changing every couple of weeks, and the timing chain will last forever.

Its gives intervals...

I agree that the manuals suggest poor run time intervals when it comes to replacing certain components, the manual for my '09 states that the piston should be replaced every 5th race or as needed. There's no mention of when the cam chain ($18 from Yamaha) should be replaced, only that the "timing chain and camshaft sprocket should be replaced as a set".

I ride MX in B/Intermediate and Vet, I'm going to replace the piston in my bike now when it's got 80 hours on it. I waited until I had 110 hours on the last one and had started to wear through the nikasil on the cylinder and had some ring float as well. For $140 it's pretty cheap insurance.

If you're putting around in some trails, I might wait a while longer.. If you're more aggressive in the trails or riding MX I'd replace it. Some people will say the opposite... but I don't ride their bike(s) or have to pay to repair them.

I agree that the manuals suggest poor run time intervals when it comes to replacing certain components, the manual for my '09 states that the piston should be replaced every 5th race or as needed. There's no mention of when the cam chain ($18 from Yamaha) should be replaced, only that the "timing chain and camshaft sprocket should be replaced as a set".

That's my point. A ridiculous interval is given for the piston and none for the chain. Then it says the sprockets, none of which is serviceable independent of the part to which they are fixed, should be replaced with the chain. Sorry, the manual is no help here, move along.

My manual says as required....if its required then do it...simple

I would definetly do the cam chain. As far as the piston, I'd say 100 hrs is a good time to change it, but I've heard of them going much longer.

My manual says as required....if its required then do it...simple

The 2010 manual doesn't say that.

I dont have a 10 manuel so

I change my piston out every season. and a timing chain twice a season. but I also ride or race MX in the A class every weekend so I might be on the bike more than you.

Edited by mxskater56

That's my point. A ridiculous interval is given for the piston and none for the chain. Then it says the sprockets, none of which is serviceable independent of the part to which they are fixed, should be replaced with the chain. Sorry, the manual is no help here, move along.

I know that was your point..... that's why I posted what I did... And I still agree with you.

Thanks guys. I think i will wait till about 130 hours and then change it. I will just keep an eye on the bike till then. :bonk::smirk::lol:

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