It's a .50 bore from stock type on eBay .50 piston kit weisco should be around $120 I believe you get rings gaskets and wrist pin circlips and the piston is a higher compression ratio..

 

11:1 ratio high compression

 

I just looked they have one for$140 but gaskets are separate weisco is all I run in all my bikes when I rebuild one I will settle for a stock also but no more namura had bad luck with them and it also said 85.50 is stock for the 400ex it's going to be a tighter fit for the compression ratio difference you're going to be glad you got the weisco it's worth the money

 

I ordered new piston rings , a full moose racing top end gasket kit, oil filter and oil.. can't spend a lot of money at the moment on it.. but I'm hoping this will fix the problem

 

Should unless you have a warped head or jug that could be a possibility. Just be sure to torque everything 2 spec good luck

 

Thanks for all the advice.. I will definitely torque it down right

 

Let's just hope it's not warped

 

Your welcome and hope it works out for you

 

It's gotta work it's a honda.

 

Runs perfect now!! But it makes a loud ticking sound