Top-End

[VCHSS4]

Do any of you know what parts you need to rebuild a top-end and the cost?

 

[yzmarcimus]

Do any of you know what parts you need to rebuild a top-end and the cost?

You need a piston kit, and a top-end gasket kit, cost of around $100 for a 125. The piston kit usually includes the piston,ring and wrist pin, the gasket kit includes the cylinder base and head gaskets, new pipe o-rings and anyting else particular to your model and year.

 

[Studboy]

And usually a wristpin bearing. (~$18).

 

[VCHSS4]

Thanks for telling me. I thought that the whole cylinder had to be replaced also.

 

[Studboy]

Only if it is way out of spec or extremely damaged. You should take some measurements before you put it back together to determine what you need to do. Does it have a sleeve or is it plated?

 

[VCHSS4]

It has a Nikasil bore. Replating is needed for oversizes.

 

[VCHSS4]

Does the rad valve and reeds need to be replaced also?

 

[Peer Lovell]

Does the rad valve and reeds need to be replaced also?

Reeds only need to be replaced if they are chipped or curled or don't snap tight against the body of the valve.

 

[Jaybird]

You are riding an old bike. You would be miles ahead to purchase a book like Eric Gorr's, Motocross & Off-Road Performance Handbook.
He covers just about all the issues concerning top-end rebuilds with narratives and pics.
The book also covers many other area's off bike maintenance and is, IMO, invaluable to the novice wrencher.
A very good investment.

 

[VCHSS4]

What do you need to put the top-end together if it is blown?

 

[Studboy]

Describe "blown". Worn out, seized, or blown to pieces?

 

[MXSparx]

Start HERE
Lots of great info for the do it yourselfer