how would i cool my 2.5 down......i run the engine rich and it sputters and go's slow and when i lean it out it dies i think because of heat.....i take off the body and i can feel it........help me

Of course make cool openings in your body, both front and rear window, also rear side windows if possible.
Run in engine, en put head in the right direction (opening in drive direction).

If you put the carb leaner always turn the adjustment screw 1/8 turn max at a time, then run one fuel tank before putting any leaner.

Good luck, take care.