MarineDiesel repowers their first Riddle Marine jet boat. Riddle Marine was approached by future boat owner, Andy Chimilinski, and inquired about getting a boat on order with a diesel engine. This 8000lb 23ft jet boat is typically powered by a 8.1L 496cid gas engine. They were looking for a diesel engine option that would match the footprint of the big block gas engine, maintain the performance, burn less fuel, be able to use the same Hamilton Jet, and stay within the same packaging dimension as the 8.1L gas would be. The Hammerhead RPM series MD330 engine was the engine of choice which was coupled to a Hamilton 241 jet.. With 330hp at 4000 RPM and 515 ft-lb of torque at 1800 RPM the boat cruises at 28 mph at 2900 RPM and a top speed of 40 mph. The MD330 burns about 40-50% less fuel than the 8.1L 496cid gas engine.