Couple other advantages of the YS engines. One really does not half to worry about fuel tank/carb placement/arrangement. One can put the fuel tank over the CG if wanted due to the pressurized fuel system. Once tuned properly... The engine really doesn't care what position it is in no matter what you throw at it in the air. The needle setting stay the same through the entire tank of fuel. Great power as Airbusdrvr pointed out. Can turn a good size prop too. The biggest thing to remember though about YS engines is do not use a after run oil that is petroleum based as it will cause the seals in the regulator to swell. Good engine