there is no yes or no, in your manual it will give you the max runout specs on pistons clearance, and ring end gap clearance. You should check those while you are in there. is the piston is OK, and the rings are little bit towards the end of the spec, go ahead and toss in some new rings. Make sure you get to the right rings, ie if you have a standard piston, use standard rings, 1st oversize, 1st over rings. Some times you can clean the top of the piston off and it will be stamped on it, some times you have to measure it. If it looks like its never been open its probably standard.
Now, if you do put new rings in it, you want to give it a light hone, it's easy, and the hone tool is pretty cheap.
http://www.amazon.com/Engine-Cylinde.../dp/B000I12TY6
or the better option is to measure the bore (or look it up in the service manual) and order a ball hone, they are about the same price, but will only be good for that size cylinder. FOLLOW THE INSTRUCTIONS ON THE HONE!!!! do not hone for too long. you are pretty much "breaking the glaze", google how to hone a cylinder.
yes you can use your stock pistons and rings, but my logic is, why you are in there...why not?
also, if the piston is out of spec, you will need to go to an oversized piston, and have it bored out. You might have to mail it to a machine shop, search around on line. most all auto machine shops will do it.
finally. CHECK YOUR RING END GAP OF YOUR NEW RINGS. I cannot stress this enough. here is a pdf write up.
http://www.wiseco.com/PDFs/Manuals/RingEndGap.pdf
they show a ring gap grinder, you can do the same thing with a file
F.U.2 RACING
Atc90, bandito frame
Atc185 x2
82 250 (300 kit)
83 250R
200ES Big red
Atc200X (with lifan motor)
