Save hundreds over Rotax E - The AK7 gearbox is the same basic unit as the SPG4 unit sold by Air Trikes in Canada for the past two decades for their GEO Suzuki, Subaru and BMW aircraft engine conversions.  After Mohawk started using these gearboxes extensively, Tango Gyro in Atlanta began  selling them as their "SPG" unit.  
 
None of these three gearboxes is interchangeable with the other, though they are all based on the same basic Airgear Type B unit.  We order our unit with a proprietary alignment groove, milled into the rear mating face at the same time the manufacturer mills the pinion shaft bearing housings, etc., thereby providing perfect alignment mating to a tab milled on our MAC GTAdapter plate in-house in our Columbia shops.   Our pinion shaft is a shorter length as well, to accomodate our adapters and shaft couplers.  You will not be able to use a Tango or Air Trikes gearbox with any of our our YG2 or YG4 adapters unless you request it at time of order.  
 
The stock gearbox at the price listed includes mounting hardware and a 75mm prop flange.  A Rotax Standard M8 or AN5 x 4" on-centers prop flange is available for an additional cost of $200.00.  SAE 1 or 2 is also available on special order. 
 
Price includes stock gear ratio of 3.0:1.  3.47:1 gears are available for additional charge, call for price. 
 
Price subject to change without notice.