the 91 will be oil cooled only! the 93 will be watercooled, the first year that suzi made the waterboiler 1100 for the US. watercooled bike is heavy try comparing the weight of it to a modern day cruiser of around 500lbs. great bike for streamlining on the highway, but not so good for tight turns(racing style) Big powerfull motors In 95 they changed the motor a bit to get more power they lasted up until 98. Then the busas took over the 91 is a good candidate for blower purposes for drag racing the 93 can have a blower to. these bikes can be bought and modified on a low budget and still spank most stock busas but take extreme modifying to play king of the hill. Oh yeah these bikes usually start out around $3000k for nice ones. hope this helps