Motorcycle Repair: no compression, honda 4 wheeler, combustion chamber

Question
my stepson has a 1985trx125 honda 4 wheeler and it has no compression at all , maybe u can help me by sending a diagram of how to pull off the jugg to check out the piston ,not sure how to go about it ,  hopefully u can help me i really need it ,

Answer
Hi John,

I can send some tech files on the topic, but I'll need your email address as requested and explained in my instructions. I would perform a leak-down test to identify the source of the leaky combustion chamber.

You'll need a copy of the service manual (repair manual) for specific details about inspecting the top end. You can find service manuals on eBay and other on-line retailers. Also, many public libraries offer service manuals.

You'll need a 2"-6" micrometer and dial bore gauge or equivilant to measure piston and cylinder wear. It's best to leave these parts assembled for tech inspection if you're not experienced with the work.

"www.atvfrontier.com" is a great ATV resource.

Respectfully,
Mark Shively