Yamaha Genesis (YG) Engine

Gearbox Mounting Adapters

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Engine Type:  Adapter Order ID
YG4    APEX:  GTI  $1500.00
           RX1:  GTA $1500.00
YG3      All:   GTB $ 650.00
YG2 Phazer:  GTC  $ call for price  
Gearbox Options, add "-XXX"
MAC AK7:         -AK7
AirTrikes SPG4:  -SPG
Tango SP:          -TSP
Rotax C:            -RTX
Simonini C:       -SMC
Arrow:             -ARW
Hirth:               -HRT
Other:              -TBD
Apex GTI-RTX adapter with Rotax C PSRU mounted
This kit was shipped to Steve Henry for installation on the Wild West Highlander "Yee Haw 6" in 2017 and is available for inspection at Oshkosh 2018.  This was the first successful Yamaha APEX adapter ever installed by anyone, anywhere in the world. In 2018, MAC added a precision aligning ring to the GTI-RTX adapter which snugly fits inside the Rotax gearbox housing, insuring a perfect alignment to within +/-0.0005" tolerance specs, assuring the best possible wear characteristics for the shaft connection (either clutch or flex coupler), engine countershaft bearings, and gearbox.
Yamaha RX1 with GTA-Arrow Adapter
This GTA-ARW adapter is the world's first Yamaha RX1 conversion kit ever fabricated and successfully flown, in 2012.  The Arrow gearbox has an internal sprag clutch and steel alignment ring for precision mounting.  The taper-bore drive gear attaches directly to the YG4 countershaft PTO, and although the internal moving parts are twice as big as Rotax C PSRU's, the overall length of the installed power plant is nearly identical to the that of the Rotax C, making this an ideal unit for some of the shorter fixed wing nose cowls.
GTA-AK7 adapter for RX1 and MAC AK7 gearbox
MAC AK7 gearbox mounted to the adapter and crank case cover (CCV), with a countershaft installed to show how everything fits together.  The stock YG4 aligning pin pockets on the  CCV are precision milled through the top of the pockets, and mate to pockets in the adapter collar.  M8 x 30mm pins align the engine, CCV and collar together.  In line with these pins are a second set of M8 x 16mm pins that align the universal collar to the adapter plate milled for the type of gearbox to be used.  The CCV, collar and plate can be TIG welded together to form a single unit upon request, but we have not found this necessary.  Even after an unfortunate prop strike, the parts proved to remain intact and perfectly aligned, and the unit was continued to be flown.

© 2018 by MAC

Steve Henry's Just Highlander, nick-named "Yee-Haw 6", swept the EAA Oshkosh AirVenture 2018 STOL competitions all week long.  To cap it off, on Sunday, July 29, 2018, the EAA AIRVENTURE daily newspaper "TODAY" named Steve and his airplane winner of the prestigious and coveted Light-Sport Aircraft Reserve Grand Champion award! 

Back in January 2013 Steve was our first paying customer.  Then, in 2017 immediately after we announced the introduction of our Yamaha APEX engine adapters - to attach gearboxes to the Yamaha Genesis 4-cycle, 4-cylinder, liquid-cooled, fuel-injected, 150 HP engines (YG4i) - Steve was the first to order one.  He finished his YG4i conversion and Highlander airplane build, and had it flying in 2017.  This year, Steve flew it to Oshkosh for AirVenture 2018 from Nampa, Idaho, some 1700 miles one-way.  

We are proud to be a small, but key, factor in Steve's extremely successful Highlander Yamaha APEX project, and to share his joy with everyone in this once-in-a-lifetime award (one cannot win in any category more than once). 


This is what innovation for EXPERIMENTAL AIRCRAFT is all about!  Congratulations, Steve, and "Yee-Haw!!!"  

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Mohawk Aero Corps (MAC) was the first shop to build and fly a Yamaha Genesis 4-cylinder (YG4) 140 HP YG4 aircraft in 2012.  We were the first to start selling RX1 snowmobile engine (YG4) conversion kit parts, in 2013.  In 2015 MAC was the first to fabricate a purpose-built PSRU for any Yamaha conversion, the Silent Drive which uses Hy-Vo chain and prop strike protection technology. 


Then, in early 2017, MAC was the first to produce and sell a conversion kit for the fuel injected, 150 HP Yamaha Apex snowmobile engine, the YG4i.  We continue to this day to be the ONLY, EXCLUSIVE, provider of APEX engine conversion kits!  Our Yamaha conversions kits are now being used on the world's most powerful aircraft engine, pound-for-pound: Steve's 190 HP "Yee-Haw 6" which weighs about 170 Lbs. installed, all-up, plus NOS bottle & plumbing.  

MAC has been imitated and copied, our Yamaha adapters re-designed then sold by others.  But no one has come close to being able to match our flawless in-flight record of ZERO gearbox, clutch/ shaft coupling, and/or engine failures to date, making our exclusive Yamaha conversion products second-to-none.  Independent consumer reports of in-flight "required related equipment" failures using our competitor's adapters is an astonishing 1 in every 3 to 4 adapters they have sold, a total of some 26 adapters.  These failures include: gearbox bearings failing in 50 hours, and another at 200 hrs; a rubber shaft coupling destroyed in 10 hrs, and another at 50 hours; a cracked clutch hub; clutch springs breaking; and clutch attachment screws falling out.    


MAC has had zero failures and sold 21 conversion kits as of 7/31/2018.

Your safety IS our concern!  







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