Yanmar makes good small & medium size engines. That is what powers much of the John Dere equipment line, and in the smaller tractors Yanmar does/did build the whole machine. Yanmar is the most commonly used engine in sail boats under 60' and making some inroads in power boats as well. You have to choose the right one and do the instalation properly or it won't matter how good the engine is.

i dont have 1 but i worked 1 day with a guy that had it in his shorthood and he also had 300d controls put on it said it cost him 7k for the motor and controls installed we burned 5/32 7018 all day long and at 3pm that afternoon his rig started burning cold and my old redface was still stacking them in i doubt it was the motor it was in his fancy 300d controls i'm sure he said he uses about 2 gallons of fuel a day