World's First 160 HP Yamaha EXUP Aircraft Engine!

NoWingsAttached

Unobtainium Member
Joined
May 21, 2006
Messages
4,871
Location
Columbia, SC
Aircraft
Air Command Tandem w/ Arrow 100hp; GyroBee w/ Hirth 65hp; Air Command Tandem w/ Yamaha 150hp
Total Flight Time
>350
Yesterday, March 25, 2020 I revved up the first ever aircraft conversion Yamaha Genesis 4-cylinder (YG4) with EXUP titanium, computer-controlled, valved exhaust - which produces a whopping 10-30% MORE POWER across the mid-range power band than conventional YG4's. This Air Command Tandem gyroplane YG4 install was built for PRA Chapter 18's Geoff Resney. (Geoff would be on his way to Columbia right now if it weren't for COVID-19, dang it.)

The engine weighs about 170# all-up, with exhaust, radiator, wiring, hoses...the works.

For more information please email [email protected].

Thank you,
Greg



Please click on the link below for video.

Mohawk Aero 160HP EXUP Yamaha YG4
 
Nice and quiet.
 
Greg, what engine RPM, propeller RPM is that in the video? "Full throttle"?
What PSRU?
How much ?
Thanks for sharing.
Brian
 
Greg, what engine RPM, propeller RPM is that in the video? "Full throttle"?
What PSRU?
How much ?
Thanks for sharing.
Brian
That was 5000 ERPM, 1355 PRPM. Just the first run up. Not even enough to take off. Since then I've tested it to 9000 ERPM, 2440 PRPM. The brakes and the chocks won't hold it after that, had to shut it down until I get it out to the airport and tie her down proper. It's a silver-tongued beast!

My neighbors love it. People walking their dogs stop a safe distance away to hang out and listen/watch test run-ups. Guy across the street came over after I had her up to 8000 ERPMs on Sunday, begged me to drive it up and down the street for him.

Hmmm....nah.
 
680 lbs. thrust measured at ~72°, ~25% H, 195' MSL, dead calm, 20# dialed in to account for the measured initial ground rolling friction, maxed out to 9800 ERPM/ 2655 PRPM, 68" 3-blade Warp Drive 10° pitch measured at tip.

The power band drops off at 10,700, so still have another ~1000 ERPMs left on the table. I'm going to install a brand new Warp pitched at 9.5° next and see how that does.
 

Attachments

  • IMG_8446 (480x640).jpg
    IMG_8446 (480x640).jpg
    63.8 KB · Views: 18
I am very familiar with this motor having had a few R1’s in my time, Yamaha have a good rep for bullet proof engines, what Rpm do you have in mind for the Cruze of the gyro?
rotax we fly say 5300 - 5500 in Cruze with a side by side gyro and the engine is happy, so I’m keen to hear where yiu will find the happy medium for the R1 engine?

will it be available to purchase from you as a bolt on replacement for our rotax when we wish to upgrade or TBO? Will you be able to suppply a prop with it?

all the talk and hype around the new 915 ...yet it has a TBO of 1200 hours ... so I’m watching this development and giving you a big thumbs up.
 
Ha - I clicked directly on the photo without reading your text and was excited to see that. Then I read your text. Oh well.. yes - that would be nice way to reduce the cost and keep performance.

I didn’t know the 915 only has TBO of 1200 hours. Ouch.
 
Ha - I clicked directly on the photo without reading your text and was excited to see that. Then I read your text. Oh well.. yes - that would be nice way to reduce the cost and keep performance.

I didn’t know the 915 only has TBO of 1200 hours. Ouch.
 

Attachments

  • EA327E01-7EF8-474B-AB53-E0A6C8701FBF.png
    EA327E01-7EF8-474B-AB53-E0A6C8701FBF.png
    93.9 KB · Views: 25
I have seen on our local sales agent web site as well that it’s marketed as a 1200 TBO ....this tells me a few thing about it I would rather not want to know, at the price a nice to have ..... but it’s not cheap and I think it’s great that we have top engineers tinkering with alternative power plants.
I appreciate Subaru have been a chosen plant in many installations but considering the high rpm it’s having to maintain in a gyro I have my concerns, Yamaha, Honda and Suzuki we can’t break them when we are full of jungle juice and we ring there necks hard on a track when we race our bikes so who knows this may be the way forward.

👍
 
When I started doing this in 2011-2012 all I heard was "They turn too fast. They will never last."

Yeah, right.

It is now eight years later, 2020, and like the battery bunny pounding his big drum they just keep on going. And going. And going. And...

Rotax is a great engine. So what? 912 weighs THE SAME as YG4, yet it only puts out 100 HP while the YG4 puts out 140-160HP, depending on year built. And you can buy 8 Yamahas with 50-100 hours on them for the same price as a new 912. Guess what? Every one of those slightly used Yamahas will outlast a brand new Rotax TBO. Every time.

A 914 that puts out 115HP for 5 minutes before it turns into a grenade weighs about 15 lbs MORE than YG4, and you can buy at AT LEAST TEN YAMAHA YG4's for the same price as a new 914, and each of those TEN Yamahas will outlast that ONE Rotax every single time.

Now, who cares about a 915? Well, Rotax FINALLY built a engine that puts out what, 135HP - or is it now 140HP - that costs well over $35,000 and weighs something like 187 - 195 lbs and costs $10,000 for a TBO after 1200 hrs.

$45,000 dollars for 1300+ hrs useful life, at 190 lbs and ONLY 140hp? Are you kidding me? I can buy FIFTEEN 150HP Yamaha YG4 Apex engines for that much money, and I will get 22,500 hours out of the lot of them, and still save $$$$$ fuel money (YG4 = 4.5 GPH at 75% throttle) and get FAR better performance and it weighs 20 lbs LESS.

But I'm either preaching to the choir on the one hand or talking to a box of hammers on the other.

It does no good to try to tell people that a Yamaha is a far better choice than a Rotax, because...I don't know, go ahead and give me ONE good reason to buy a Rotax. Because I have not found a single, solitary GOOD reason to buy one yet.
 
BREAKING NEWS:

The world's most powerful, completely stock, normally aspirated, 160HP Yamaha EXUP (titanium variable tuned valve exhaust) installed engine weight ~170 lbs is FLYING as of tonight, Sunday May 17, 2020, 7:23 PM EDT.

Once again, the gyrocopter community has blasted through the barriers and done it FIRST - AGAIN!

Gyroplanes rule.
 
Last edited:
BREAKING NEWS:

The world's most powerful, completely stock, normally aspirated, 160HP Yamaha EXUP (titanium variable tuned valve exhaust) installed engine weight ~170 lbs is FLYING as of tonight, Sunday May 17, 2020, 7:23 PM EDT.

Once again, the gyrocopter community has blasted through the barriers and done it FIRST - AGAIN!

Gyroplanes rule.
This is great news
myself a great fan of Yamaha ....as for your comments on rotax👍But we are brainwashed it’s the best just like they brainwash us users on what oil we have to use

put motul into any Yamaha or jap bike no drama, put it in a rotax and lose your warranty 😳
 
Show me the highest... documented.....trouble free Yamaha aircraft conversion with no repairs. Truly documented. I’ve been asking for years....hours in service prove reliability.... nothing else.
 
The phrase "Herding cats" comes to mind, and I can't give you "nothing else", either. It is difficult to find a gyro pilot who flies more than 50 hours a year, let alone hundreds on a single craft like many FW pilots do.

I approached you about installing a Yamaha engine on one of your projects and your response was, "I'll never put a Yamaha on anything I own." Oh, well. I gave up on you, figured it's like trying to convince a Democrat to vote for Trump in 2020, or a Republican to vote for Biden.

The only problems I am aware of with Yamaha conversions have all been with the connections between the engine and prop.

Rotax gearboxes that other folks like to use on them (I typically use a Russian-built MAC AK7 and we have seen zero failures with this unit to date, unless a customer requests a Rotax or some other PSRU) have been known to fail at least 6 times and needed to be rebuilt with new bearings.

Any installation using a clutch - no matter whose clutch it is - is going to need attention.

This gyro installation uses no clutch, and is entirely mainenance free where that is concerned.

I am the only source for a clutch-free solution for all RX1 and Apex YG4 conversions ever built and sold by anyone suitable for gyroplane installation.

"I'll never put a Yamaha on anything I own ???? Really ??


For the record I have ridden the jesus out of 3 R1 Yamaha, I tried to kill a Thunderace as well back in the day these motors are F&((%Kin bullet proof and I would put a Yam on anything if I could. Rotax comes from Austria, I own a KTM as well and the engine is not the same hard core like we get from Japan! with them Austrian's also dictating what Oil we must use!
In a gyro the R1 engine will sit at same stable Rpm, and I think it will run for ever? unlike a bike where we rev it hard for short blasts over and over
Well done on this fantastic achievement

Currently I ride the Ducati Panigale Flag ship and I will not put that on engine a lawn Mower FWIW

You guys should be supporting No wings for his efforts I will jump to put a R1 motor on a gyro if I could get it past our local CAA I am loving this thread!
 
Greg, I asked above, but didn't get a direct answer to my question about cost. Per your 'divide by 8' above, it would seem your engine is approximately $2750. How much is the Russian PSRU?
Every time I check your website, it indicates that there are no engines/PSRU's to sell. ??
How different is the Apex engine from the R1 (1000cc) engine? Interchangeable?
Brian
 
"I'll never put a Yamaha on anything I own ???? Really ??


For the record I have ridden the jesus out of 3 R1 Yamaha, I tried to kill a Thunderace as well back in the day these motors are F&((%Kin bullet proof and I would put a Yam on anything if I could. Rotax comes from Austria, I own a KTM as well and the engine is not the same hard core like we get from Japan! with them Austrian's also dictating what Oil we must use!
In a gyro the R1 engine will sit at same stable Rpm, and I think it will run for ever? unlike a bike where we rev it hard for short blasts over and over
Well done on this fantastic achievement

Currently I ride the Ducati Panigale Flag ship and I will not put that on engine a lawn Mower FWIW

You guys should be supporting No wings for his efforts I will jump to put a R1 motor on a gyro if I could get it past our local CAA I am loving this thread!

Oops - meant to add something to this original parry of mine in response to Barry's jab, and deleted the whole darn thing. Please refer to this gentleman's reply to my reply, if you will, for reference. I can't just copy and paste it back into proper sequence.
 
Last edited:
Greg, I asked above, but didn't get a direct answer to my question about cost. Per your 'divide by 8' above, it would seem your engine is approximately $2750. How much is the Russian PSRU?
Every time I check your website, it indicates that there are no engines/PSRU's to sell. ??
How different is the Apex engine from the R1 (1000cc) engine? Interchangeable?
Brian

Last question first: The MAC YG4 conversion is not based on a motorcycle engine, it is strictly snowmobile engines. No personal watercraft, either. None of these are interchangeable with the other. All totally different animals.

I have recently sold several YG4 150HP engines for under $2400 - $2600 USD.

I degrease, plug all holes and bead blast, and seal aluminum surfaces to prevent oxidation and enhance appearance for $600, plus cost of parts to replace spark plugs and filters. This includes critical work that most individuals miss: The coolant return tubes must be removed, cleaned, and sealed (painted), and new O-Rings installed, and the retaining M6 socket cap screws drilled and safety wired. In some cases, especially older engines, the O-Ring seats must be refurbished and "over-sealed" by implementing a special procedure I have successfully developed (trade secret). This additional work is $28.50/hr, 2 hrs. billable time.

MAC YG4 kit includes adapter, shaft coupling and AK7 PSRU sells as a kit for $3195.00, complete.

Individual components: AK7 PSRU $1795.50; MAC Shaft coupling $449.95; Adapter $1299.95

Wire loom, with your core: $395.00

Exhaust for gyrocopter, complete, using your stock RX1 or Apex snowmobile exhaust and muffler (in good condition) from the sled as a core, as shown on the gyrocopter at www.MohawkAero.com $795.00

Gyroplane YG4 engine mount kit: $795.00

Typical budget for a MAC YG4 150 HP Gyroplane kit, complete, is under $7780.00.

EXUP 160 HP kit is dependent upon the cost of these newer engines delivered FOB to MAC in Columbia, SC.

***********************************************************************************************************************************

The MAC webpage it was posted years ago and I haven't gotten around to updating it. I should probably hire a webpage person.

Available engines: the list changes every week, please email and request current prices of available engines.

The www.MohawkAero.com web mall provides an easy contact source found by searching the words <Mohawk Aero> on your browser. Once at the Mohawk Aero Corps site for Yamaha conversion power plants and parts you can then just simply fill in the contact form found at the bottom of the MAC home page, include as much info about how to contact you, your full name, your aircraft type & make, and hit <SEND>. I always respond within 24 hours.

Or send email to [email protected], and include the aforementioned info I need.

I would like to express my gratitude and much appreciation to Jon Carleton for his FREE help with my Mohawk Aero Corps mail server solutions for the last seven years.

JOIN THE CORPS TODAY! (Mohawk Aero Corps, that is.)
 
Last edited:
My friend (I know, right? Wonders never cease) Scott McNeil provided a lot of help Monday May 19, 2020 and took this video of the third crow hop (test flight) of the WORLD'S FIRST AND ONLY Yamaha EXUP 160HP aircraft, built by Mohawk Aero for Geoff Resney of CH18.

Mohawk Aero Yamaha 160 HP EXUP Air Command
https://youtu.be/n0jmIPf9Ctc


This is at Columbia, SC Owens airport (CUB) while a storm was moving in. In fact it occurred to me as I was flying this run just exactly why I like a windscreen as the first few rain drops were kissing my cheek.

I would like to express my gratitude and appreciation to Scott for his driving up to CUB on SEVERAL occasions for aborted test attempts prior to this successful one. He lives 40 minutes away, on his family's private airfield, one of SC's oldest, in fact - SC03. Scott's dad is a gyrocopter guy from the old days, and Scott grew up with gyros. He and I just recently drove to and spent a day with Jon Carleton at 4A4, Polk County AP in Cedartown, GA him getting a lesson and me getting a biennial. That day Scott purchased a brand new Tango Gyro from one of our club members, "Billy Gyro". Our best wishes for your health, Billy. Hope all is well and hope you return soon to be able to fly gyros again, bro! Scott now has an ELA, a Trendak, a watchamacallit stick-built Bensen sumthin SxS, and last time I was in his shop Max Wilde's Subaru-powered tandem was in there. I'm quite sure I am missing two or three other gyros, but those are the ones that stick out in my memory. Oh, there's a Cavalon, too. I know, right?

Scott, with his wide array of gyro projects described above, me, and another guy now loosely form the South Carolina Gyro Club, or actually SERA (South East Rotorcraft Association). The other guy is Tony Mattioli. Tony occupies a hanger facing mine at CUB. He owns a FW, and just acquired a new Silverlight AR1 which is still in FLA. We COULD have another fellow, who lives just ten minutes away from me, but THAT guy keeps Chris Burgess' old Snobird (the one I trained in up in Frederick, MD in 2005) at Barry "He whose name shall not be spoken" and the Barnstormer's hanger WA-A-A-A-A-Y the heck up in Wadesboro, NC for reasons I can understand - Barry is a super cool guy, and the fellow gyro pilots that congregate up there are too cool for school as well. A good group, great support, and - well - I can't offer nearly as much as they can to help him out.

I am SOOOOO glad that I beat Tony to the punch of being the first gyro guy flying out of CUB in many years.

Oh, BTW: Emilia Earhart flew into CUB way back in the the 1930's in a Pittcairn! There are photos in the FBO! Pretty cool, huh?

Dear Barry: Yamaha RULES, Rotax drools. That's all I'm gonna say. Read 'em and weap, buddy, my gyrocopters will out-climb ANY gyro in the sky, anywhere in the world today. Period. End of story. Luv ya, bruh. Oh, and Ferarri? Fuggeddaboudtit. I have one word for you: PORSCHE! (especially blue ones)

Greg has left the building.
 
Last edited:
Top