Have Eric do his porting magic,and have him do a AMA legal 2mm overbore. He did it for my sons 98 YZ80, and it rips. As a matter of fact he raced against a bunch of 02 YZ85s last weekend, and not only did he pull a great holeshot, but up a big hill they couldn't pull him. Finished 3rd OA. You could also have him take it up to 100cc if you want a decicated supermini. I believe RPM has a 105, and 112cc kit, but for big bucks. For about 300 bucks (including a piston kit!) Erics work is hard to beat. Good luck.