I have a 250cc Kazuma Cougar and under a load such as pulling a mower deck or trailer, and small regged trailriding it is overheating. I have the fully automaic model with the hand reverse and small radiator.
i would also like to know what makes you think its overheating, do you install a temp gauge? if not you can buy a inline temp gauge off of e-bay for around $50, under a load it's normal for the fan to run, also normal for the overflow bottle to fill.
for your imformation your engine on the kazuma is a 85-88 honda cn250 clone. these engine were made for the honda helix motor scooter