Thunder Tiger engine race-proven powerplant is mated to a lower unit utilizing the best gear ratio and flex-cable technologies. A special set of precision helical gears transfers all the power from the crankshaft to the flex-cable, resulting in substantially reduced cable wear and maintenance, while the integrated expansion chamber / muffler reduces exhaust noise. The engine mount allow adjustments to both propeller depth and angle.
To top it off, a Prather S215 prop is included.
The PRO-21M-OB (No. 9567) is equipped with 1.19: 1 gear ratio