03 Rebuild Tips or Tricks

Hey guys just getting ready to rebuild my '03 yz450f. New parts that I am installing are a new Hotrods crank and rod along with a CP mid compression piston. The head, valves and cam are going to stay stock for this year. I have one concern about the cylinder, it has a bit of an edge worn at the top and bottom of the stroke. I have honed it but can still feel the lip at each end. Should I be concerned??? does it need to be re-plated? There is no flaking or other problems in the bore that I can see. I do not know the hours on the bike as I bought used in Dec. It will be used for trail riding and some mx track but I am by no means gonna be pushing the bike all out.

Thanks.

I'd measure that cylinder if I was you. If you honed it and can still feel a ridge, the cylinder probably needs replated.

Also, don't forget to replace the oil pump & rotor while your at it, and replace the cam chain too. :)

642 is right. The plating is a very thin layer, and if you can feel it, the wear is serious.

Thanks again guys. I am going to measure the bore on and off the ring groove and see how much wear there really is. I think there is about 5 thou of plating normally. So I will make my decision there.

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