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World's First 160HP Stock Yamaha Aircraft Engine is FLYING!

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GTX_Engines

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Joined
May 17, 2013
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34
Location
Columbia, SC
Mohawk Aero Corps has completed and successfully test flown (after extensive ground running of the power plant) 2 hours off of their newest Yamaha conversion engine offering: the 2011 - 2018 model years for the 160HP Apex EXUP snowmobile engine, with titanium headers incorporating an ECU-controlled valve for variable exhaust pressure tuning throughout the power band, resulting in more mid-range as well as top-end power.

Mohawk Aero Corps (MAC) has been building Yamaha Genesis (YG) 4-stroke (snowmobile engine) conversions longer than anyone in the business. By now there are more than 200 Yamahas flying here and abroad.

In 2012 MAC built and flew the first successful (4-cycle) YG 4-cylinder, a 145HP engine taken out of a 2003 RX1 with 2,000 miles on the sled, and installed on an Air Command gyroplane. That YG4 engine is 998cc, liquid-cooled, with both electric and liquid carb heat. The installed engine with electricals, oil tank, radiator, all the plumbing, starter, and intake silencer plus complete exhaust less muffler weighs just 165 lbs dry - the same as a 100 HP 912 Rotax, and at least 20 lbs lighter than a 110HP 914 which can only be run at WOT for a few minutes. The YG4 engine runs at just 2/3 its rated RPM at WOT, power band determined by the cam grind and timing and reduced to accomodate the stock sled clutching. It sports an internal gear reduction to a countershaft equipped with a harmonic damper that Yamaha spent two full years developing before bringing the engine to market.

It is like Yamaha was thinking of aircraft when they designed this beauty! An internal rubber harmonic damper - what more could you want in an propeller-driving engine?

The Air Command YG4 became highly regarded and very well known within the gyro community instantly. The Atlanta MIDO rotorcraft division ( 3 gentleman lead by the former chief engineer of Eurocopter) visited the MAC facility at KCJT, and upon providing certification the leader gave Greg his business card and said, "This is one of the finest home-built aircraft and engine conversions I have ever seen. The only thing I would suggest is that you clean up the stock wire harness once testing is complete and you determine what can be safely stripped out and eliminated. Here is my card. If you ever have any problems or get called by the FAA for anything whatsoever, tell them to call me."

The following year the builder/pilot and owner of MAC was voted to the Board of Directors and then Secretary of the national Popular Rotorcraft Association, the oldest and largest rotorcraft club in the the world, established in 1956 by Dr. Bensen, designer/engineer/builder of the first personal aircraft type gyrocopters. (A gyrocopter is an open-frame machine, sometimes called a "stick gyro", whereas a gyroplane is enclosed with a fuselage and sometimes a full canopy. The FAA recognizes only the term gyroplane in their documents and regulations, however. Eurotub is a name coined by the gyro community to describe the later, far more expensive models of semi-enclosed gyroplanes which became first known in the late 1990's, made by Magni of Italy, and skyrocketing in popularity since 2010.)

In 2017 MAC built the first Yamaha Apex 150HP YG4 conversion kit for Steve Henry, who went on to win every STOL race and the vaunted Grand Champion Award at Oshkosh 2018.

In 2019 MAC built and sold the first production Yamaha Phazer YG2 80 HP, installed on a Quicksilver float plane owned, built and flown by Gil Audibert of New Orleans. Video of the aircraft taking off and landing on the waters of the bayou can be found on the MAC's Youtube channel <GTGyro>.

Coincidentally, Gil and Steve both own crane companies! I know, right - what are the chances?

No other design engineer/builder has pioneered and/or produced more different types of complete YG aircraft engines.

Special aircraft wire looms available for all kits offered. No one can beat our prices, our history, our wide range of engines supported, nor our rigorous test requirements and regimen.

This includes YG2 80 hp, YG4 carbbed 145 hp, YG4 150 hp injected, and now the all-new YG4 160HP EXUP.

Email Info@MohawkAeroCraft.com for sales and information. IMG_8500.JPGIMG_8499.JPGIMG_8492.JPGIMG_8499.JPGIMG_8492.JPGIMG_8495.JPGIMG_8494.JPG

Mohawk Aero 160 HP Yamaha EXUP first flight
 

GTX_Engines

Active Member
Joined
May 17, 2013
Messages
34
Location
Columbia, SC
Video of the Yamaha 160 HP EXUP flying at CUB airport in Columbia the other day, sounds great - MUCH quieter the 150 HP IO-320 belonging to my buddy that took off right after the gyro did, although Scott didn't catch it on the vid <sigh>. Additional info on the Youtube post. Enjoy.

Mohawk Aero 160 HP Yamaha EXUP Test Flight 5

We've been flying the Yamaha Genesis 4-cylinder family of engines w/o a hitch since 2012, in dozens of aircraft and rotorcraft.

Finally weighed the machine, it came in 132# lighter than it was with the 130 HP Subaru, just 618 pounds dry calculated, 670 lbs actual with 5.5 gal fuel (1 hour plus 20 min res), coolant and oil, as measured just after the flight shown, all fuel first drained and then 5.5 gal added back for weighing.

Myself weighing 200lbs in flight gear, that is 870 TOW, and the machine has a TOW limit of 1250 lbs.

With "typical" solo pilot: lbs/HP = 5.44
 
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cblink.007

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Jul 7, 2014
Messages
410
Location
Texas, USA
Im guess these can be installed in anything?
We are going to use the Yamaha Apex conversion plant in our bird, originally designed around a Rotax 912ULS. I have received plenty of feedback from Yamaha engine builders and users, and we are sold. No known issues, conversion work is beyond minimal. Performance is great and the price point for Mohawk's product (approx $10,000 turn-key) cannot be beat!

To compare, I have yet to find a mid-time Rotax 912, typically in need of alot of maintenance work, for under $15,000.

Vendors for Yamaha Apex engine parts greatly outnumber those for Rotax; the parts can be found/ordered through almost ANY motorcycle shop/dealership. Also, the part price is better!

See attached comparisons...
 

Attachments

Doran Jaffas

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Joined
Jun 25, 2019
Messages
216
We are going to use the Yamaha Apex conversion plant in our bird, originally designed around a Rotax 912ULS. I have received plenty of feedback from Yamaha engine builders and users, and we are sold. No known issues, conversion work is beyond minimal. Performance is great and the price point for Mohawk's product (approx $10,000 turn-key) cannot be beat!

To compare, I have yet to find a mid-time Rotax 912, typically in need of alot of maintenance work, for under $15,000.

Vendors for Yamaha Apex engine parts greatly outnumber those for Rotax; the parts can be found/ordered through almost ANY motorcycle shop/dealership. Also, the part price is better!

See attached comparisons...
That sounds really promising.
 

Pops

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USA.
Would have to run it easy to keep the JMR under LSA speed. :)
 

cblink.007

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Joined
Jul 7, 2014
Messages
410
Location
Texas, USA
Does that $10,000 actually get you a useable engine or just more wild claims and broken promises. Please keep us posted.
Here is a screenshot of my convo with GT Mills of Mohawk Aero:

Screenshot_20200716-181244.jpg
Turn-key package for installation. I have budgeted for $10k for this package for planning purchases...

I will be linking up with a Kitfox owner flying one of these Apex engines this weekend. He has about 350 hours on his, and has had zero issues with the package...including the PSRU.
 
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Lendo

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Feb 6, 2013
Messages
514
Location
Brisbane
I would like to know what 2/3 Rated RPM is? as that reduction Gearbox looks mighty small for 160 Hp. I would also like to see that rubber damper.
TIA
George
 

cblink.007

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Jul 7, 2014
Messages
410
Location
Texas, USA
I would like to know what 2/3 Rated RPM is? as that reduction Gearbox looks mighty small for 160 Hp. I would also like to see that rubber damper.
TIA
George
I attached a data sheet at an above post. 7000RPM at 75% throttle.

Screenshot_20200716-182515.jpg
 

slociviccoupe

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Apr 1, 2011
Messages
266
Location
Palm Bay Fl.
I have no experiance with the sled version of these engines but very familliar with its marine variant and the sport bike version. Thr marine engines may offer a better cam profile. There are 2 different versions to choose from.
Also to be noted rod bolts arent the greatest. Ive seen very low hour engines throw rods out of the block. Mine did at 600 hours. But ive also seen engines with 2000 hours on them. So its hit or miss. And i cant say its neglect or abuse because i took really good care of my ski that the marine version was in. They share same 5v per cylinder, rods and rod bolts as the r1 sportbike. The marine version has 2mm bigger bore and 1052cc displacement. Also sports 11:1 compression and a 10k rpm redline as it has a gearbox on the back also like the sled engine.

But for anyone considering this id replace rod bolts with something stronger.
 

cblink.007

Well-Known Member
Joined
Jul 7, 2014
Messages
410
Location
Texas, USA
I have no experiance with the sled version of these engines but very familliar with its marine variant and the sport bike version. Thr marine engines may offer a better cam profile. There are 2 different versions to choose from.
Also to be noted rod bolts arent the greatest. Ive seen very low hour engines throw rods out of the block. Mine did at 600 hours. But ive also seen engines with 2000 hours on them. So its hit or miss. And i cant say its neglect or abuse because i took really good care of my ski that the marine version was in. They share same 5v per cylinder, rods and rod bolts as the r1 sportbike. The marine version has 2mm bigger bore and 1052cc displacement. Also sports 11:1 compression and a 10k rpm redline as it has a gearbox on the back also like the sled engine.

But for anyone considering this id replace rod bolts with something stronger.
That is good information to know! Thanks for passing it along!
 

cblink.007

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Joined
Jul 7, 2014
Messages
410
Location
Texas, USA
I want one.
We are getting ready to pull the trigger on an engine package. We just picked up a wrecked Yamaha snowmobile (here in Houston of all places) so we can rip the engine out and get smart on maintenance tasks for it. We found it on craigslist for $450, so it was a win-win. Also linked up with a local crotch rocket guru who is familiar with the plant to help us out!
 

slociviccoupe

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Joined
Apr 1, 2011
Messages
266
Location
Palm Bay Fl.
So the marine variant is the 04-08 yamaha fx high output. Its the one with the different cams and some other goodies that might cross over. Its called the mr1 if you want to google it.
Its got really nice mounts already on it, has a gearbox on back that drives a finger type coupler, also has a dry sump oil tank.

There is another variant in the vx110 watercraft but the engine has lower compression, different cams yet again, cast pistons, cast rods, and only turns 7600 rpm. Its not very desirable as it only makes 110hp.
 
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