Hi, I recently made a purchase of a 86' LT250R quadracer and I'm having some problems. The guy I bought it from said all that was needed was the float level set (it was @ 15mm as opposed to 9.9 -weird) and I guess the float needle was sticking at one point, although I never experienced this but I did blow it out with compressed air and it works fine now. Blew the snot out of the main jet, but the carbie really looked pristine. I have a fat nice spark from a brand new plug. Now comes the problem. I had the clymers manual while I was at this dudes house but it didn't say anything about compression limits, I thought it was weird but whatever - I kept on chuggin. First reading I got was 115 psi without the carb on, then later when I reinstalled the carb I'm only getting around 80 psi. Mind you this is after kicking _several_ times over. I know the tester is remotely right, like in the ball park of +-10 psi from work on my KZ400. The owner said the 115psi was about right and I trusted him, like an idiot.

So now I have the problem of fixing this badboy. Where do I start?
I have heard of some "decompression" lever that might be "sticking", I use "" because I really have no idea what that means or where I should look. I'd prefer just to take the thing out entirely, I'm certainly a strong enough dude. I have both an RD350 and a KZ400 I have no problems kicking over.
Of course I feel its more likely that the cylinder wall and piston is fried, what should be my first steps with that?

Oh yes and, whaaaadddddupppp?

 

Welcome to the party! The bar's to the left.

Make sure your checking your compression with the throttle wide open. It should be similar with the carb on and off. I don't have my shop manual with me but I'll get back to you on what the compression should be.

 

If you're under 150 it's time to yank er down.

 

OK. I took the piston and cylinder wall off the ATV. There are a bunch of light scuff marks on the piston (all around). Am I right to think those shouldn't be there and I definately caught my problem? I just wanna make sure this is it.
How much should I spend for a bore and hone? Where can I get: New oversize piston, rings, wrist pin, wrist pin bearing, and clips from?