very low compression. Need help!!

[dafish1]

Ok i have a 1996 yz 125. I got it awhile ago and i want to do some work on it. I got a compression checker to see the compression and it said it was 50 psi. I do know that my power valves leak and some exhaust comes out the power valve breather tube. Idk if its the compression checker or my bike. Would i have to change rings or replate it idk please help?

[mlatour]

The only way to find out is dis-assembling the engine and inspecting / measuring all the components versus the service manual specs.

You can only 'refurb' a top end with a new piston & ring so many times, eventually the cylinder / plating wears beyond the limits.

[numroe]

Put a new piston kit in it. Then check it again.

[YZDOC]

Also, pull top end, supply photos, we can go from there. And please, get the manual. 

[mritch8]

Try running a forged piston when you buy one after you have your cylinder measured buy a machine shop then order the according piston