Rotax B Gear Drive Box Parts Diagram

Over 90 per cent of ultrlaight aircraft using the 377, 447 and 503 engines use the 2.58 to 1 reduction drive. Ratio's of  2.24 to 1 and 2.0 to 1 are used with smaller diameter propellers. Rotax limited the use of the B gearbox to the 377, 447, and 503 engines which are 50 horsepower or less. But some aircraft manufacturers did produce their aircraft using the Rotax 582, twin cylinder, liquid cooled engine of 65 HP with the B reduction drive.

All Rotax 2 Stroke aircraft engines can be fitted with one of the following gear reduction drive units. Type 'B' Gear Reduction Drive For Rotax 447, 503 and 582 engines. Rated for a propeller mass moment of inertia of up to 3000 kgcm2. Available reduction ratios: 2.58 to 1, 2.24 to 1, 2.00 to 1.

The Rotax type B gearbox is the lowest priced and lightest of the gear boxes used on Rotax Two Stroke Aircraft Engines. It is limited to a propeller mass moment of inertia of 3000Kg/cm².

Which Direction is your prop spinning in?   
Direction of rotation is always noted from the rear of the aircraft. If you are standing behind the plane and getting blown by the prop wash, which direction is it turning? 

The following is a fail safe list to follow for rotation direction.   

For all Rotax the 447, 503, 532, 582 and 618 engines. used with ultralights:   
Pushers with gear boxes run a right turning prop.   
Pushers with belt drives run a left turning prop.   
Tractors with gear boxes run a left turning prop.   
Tractors with belt drives run a right turning prop. 

Counter-clockwise is left and clockwise is right.