Well for starters you shouldn't have bought the ody in the first place, I have had nothing but troubles with mine and most of the people here too. To make it go a little faster you could mount the air intake sideways so the air is forced into it and it will keep
it cooler and in the end run a little faster, I have a snowmobile that if it is hot it will not run as fast
this is the same for all 2-strokes. PS get rid of it while it still runs!!
"If it aint broke, ride it till' it is!"
Ok first thing is first. There is nothing wrong with the 250's.
I run Golden Spectro and never overheat, or anything. Now to your question, you can get a PowerBloc clutch, or 102c clutch. Also there is porting the cylinder, boring the cylinder for a larger piston. But you always want to run 20:1 not 32:1
I had a 250 oddyessy and I sold it becausen it had no power. After selling it I heard from the guy the exauhst was plugged! When I had it it wouldn't even spin the tires now the guy says it scares him its so fast! So check the exauhst just in case.