This is the second time I have had to rebuild the '99 KX250 in the last 3 months. I opened up her up...it's not the low end..the guy ( High Performance Racing in IL) who I had machine it must have machined it wrong because the rings were hitting on the side ports. So there are scars running down the lowest part of the cylinder. So I'm going to have to rebuild it again. Does anyone know how well sleeves work? How do they work? How are they installed? Are the a generic size and then you have them bored down? Any specific brand? Is this the right way to go? I'm running on a really low budget. Let me know all the details on sleeves please! Thanks guys!