Nutcase

Just bend up a piece of polycarbonate.

I tried those tires and they work fabulous in sand, and really suck on dirt roads. You are literally all over the road at any speed past 25-30 mph.

Ever since I replaced the plastic engine cover with an expanded metal cover (See photo) I have not had any cooling issues on the motor. It is important to blow out the radiator after every trip as the passages on the radiator are very small and plug up very easily. I also changed the rear fenders to 3/16 polycarbonate and bent them so that the wheel could not hit them in the upswing.