So where to start my son's LT80 stop running a couple months ago. Naturally I assumed I had a carburetor issues or the peacock valve. After replacing those two items and ensuring I had a spark I started doing my homework thus finding this page. After all the post I have read the next natural thing would be compression I did a compression test today and it was only 60 after spraying WD-40 in it so off comes the cylinder head and The Jug to my surprise the cylinder walls and all the gaskets are pristine so I am totally stumped no idea why I would not have compression when everything looks brand new even the Rings look great any help would be appreciated thanks in advance

 

Measure. Just because they look good doesn't mean that they are not wore.
Welcome to the forums.

 

Could just be worn rings...top end rebuild is pretty cheap and considered normal maintenance on just about any 2-stroke...kinda missing the nightmare part...crank grenading and blowing a hole in the case is nightmarish...

 

I'm not a re-ring kind of guy. If the rings are wore, I figure the piston is wore too.

 

C'on Jack...you know me...I'd never just re-ring it...a fresh top end means all the goodies...all the goodies are still cheap...

 

I know you agree, just making sure everyone knew.

 

Could be worn rings, but if there is no step in the bore---. There are other possibilities, head gasket gone, reed valves stuck or broken, just saying.

I do fit new rings to old pistons, but I am a tight wad.

 

thanks for the advice
I'm going with a new top-end any suggestions on brands and should I go bigger than stock should I replace the reeds and go with bigger jets

 

You should have your Suzuki cylinder bored to a next size bigger Suzuki piston.
Yes, you could get a china junk top end. FYI: they are all the same with different labels.
No jetting changes are needed.
Boyesen reeds are fine but not needed.

 

so what is the stock size of the piston and bore Im new to this and want to get every thing right