Coho and I have raced on flat ground on Honda 90's, his a '69, mine a 72, both in top tune. Top Speed in a crouched position with 220lbs on board is 46mph. The great thing about 90's is mileage, and trailability. They will climb anything. Before I sold my drift boat I upgraded to an XL250 so I could go 60+ on the highway. It was a significant weight difference though. Both were mounted on a rack that I built which fit into the receiver of my truck and added about 24" of space between the rear bumber of my truck and my drift boat trailer.