about cooling mechanism according to my poor knowledge there are two parent categories:
Air Cooled and Liquid Cooled
Most engines have one distinct choice of what type of cooling they have.
But there are many examples where more then one cooling system is incorporated for the engine.
In Liquid Category: Water Base/Coolant Cooling and Oil Cooling Exist
But most air cooled engines which are also expected to perform at peak RPMs are incorporated with either Water Radiator or a Oil Condensor.
For example Honda Degree XL and Honda Tornado XR (250cc category) both have exactly same engines same power but Degree was rolled out with water body (even it had AIR cooling fins) where as tornado was rolled out with Oil cooler/condenser.
DR250 is a unique design which uses Frame Just like Hondas later Dry XR's series. This reminds me of Oil and Air Cooled Night Hawk 750 of 80s!!!