Another Yamaha Re-Power Highlander is flying

For general discussion of the Just Aircraft family of aircraft.
Includes: Highlander, Escapade, Summit and SuperSTOL.
Post Reply
User avatar
marl59
Seasoned Member
Posts: 84
Joined: Thu Oct 22, 2015 5:59 pm
Location: Oakland, CA

Another Yamaha Re-Power Highlander is flying

Post by marl59 »

My local FSDO guy let me set the number of hours I would need to test and determine if all of the flight characteristics were safe after I did all of the firewall forward work. I set the flight time at 4 hours. I was running a Rotax 912ULS before with an 80" Catto climb prop. The Rotax had 1,737.6 hours on it and still ran like a top. (I'm selling it complete and the prop and spinner BTW). I'm now running a 2003 Yamaha RX1 carburated engine that had 734 miles on the sled. I'm running a Rotax C gearbox with 3:47 gearing through a Skytrax converter and a Luga 3 blade Scimtar, ground adjustable, carbon fiber prop. Ive only flown it the 4 hours so far with 3 different prop settings so I can't give an in depth comparison but here's what it looks like so far:
Rotax climb rate was 800' fpm at Vx with just me on board.
Yamaha climb rate is 1,500 fpm at Vx with me solo.
Rotax WOT cruise was 82 mph.
Yamaha WOT cruise is 103 mph and still accelerating. I backed off on account of rough air. My guess is it would top out at 105-107 mph.
Rotax fuel burn at 5,500 rpm cruise was 4.5 gph.
Yamaha fuel burn at same speed, 70mph, was 2.5 gph.
Wild West Aircraft supplied my engine mount, ceramic coated header, air box and coolant tank plus a Rotax 914 radiator.
Total cost for the project is under 14k. I mounted the engine on a temporary wood stand and worked out all of the running, electrical and radiator plumbing challenges ahead of the install because I wanted to keep flying my plane while waiting for my Luga prop which took about 7 weeks from Ukraine.
Would there be anything I would do differently if I had to do it over again? Nope. :)

Needless to say, I'm a happy pilot! Now I just have to find me a Yamaha Powered sticker to replace the Rotax Powered stickers that I peeled off!

Please don't misconstrue my meaning here. I loved my Rotax and think they are great engines. Cost was one of the major factors that made me decide to go with the Yamaha. The better performance was a bonus. And the Yamaha set up is a little heavier, how much I dont know, I have'nt weighed the plane yet. My guess is between 15-20 lbs.
You do not have the required permissions to view the files attached to this post.
Clark in AZ
Veteran Member
Posts: 356
Joined: Wed Oct 07, 2015 11:40 am
Location: Cave Creek, AZ

Re: Another Yamaha Re-Power Highlander is flying

Post by Clark in AZ »

Awesome! Thanks for taking the time to do a write up. Really impressive numbers. Be sure to report back as you get more time on it. Any troubles with it so far? Any unanticipated problems with the install or running of it?

Thanks again,
Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Another Yamaha Re-Power Highlander is flying

Post by BucF16 »

Yes, Please report back on pros and cons. I have committed to Steve for an Apex firewall forward. This will be fun integrating his setup!

Cheer,
Bruce
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
marl59
Seasoned Member
Posts: 84
Joined: Thu Oct 22, 2015 5:59 pm
Location: Oakland, CA

Re: Another Yamaha Re-Power Highlander is flying

Post by marl59 »

Going flying today after work.
All pros so far.
The only thing that some may consider a con is all of the work to make it all happen. Not a con to me though :D
The throttle conversion is a fair bit of work. My throttle travel is 2.5" and the RX1 travel is 1.125" and you have to play with return spring rates etc to get it to work correctly.
User avatar
marl59
Seasoned Member
Posts: 84
Joined: Thu Oct 22, 2015 5:59 pm
Location: Oakland, CA

Re: Another Yamaha Re-Power Highlander is flying

Post by marl59 »

BucF16,
Steve will be a great help. He and Teal and Copro, (Jody) were my go to guys when I had a question. BTW, I chose to retain my original cowling from the Rotax so I had to cut a hole in it for the header. Also had to do some surgery to fit around the radiator and header exit location. And for the gearbox up front. I like my original cowling shape so I'm willing to live with the back of the prop flange not as close to the cowling as you normally see on airplanes, about 2.5" BTW the tape I have around the header is gone now. I've learned that it causes them to rust. I did line the inside of the cowling with the self adhesive foil heat barrier from A/C Spruce, works great.
Good luck on your new project!!
You do not have the required permissions to view the files attached to this post.
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Another Yamaha Re-Power Highlander is flying

Post by BucF16 »

Outstanding! Thank you.

Now, of course T/O & LDG Distance 8)
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Another Yamaha Re-Power Highlander is flying

Post by BucF16 »

Sorry one other ? Your Luga prop is my 1st choice; However, I see there is not a leading edge. What are the issues if you encounter rain? Which in Ohio is often. I limit my wood sensenich to VERY light rain on my J3.

Thanks,
Bruce
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
danerazz
Veteran Member
Posts: 1240
Joined: Tue Aug 18, 2009 9:33 pm
Location: Bangor

Re: Another Yamaha Re-Power Highlander is flying

Post by danerazz »

Just out of curiosity, is there any issue with running avgas in the snowmobile engines? I wouldn’t think so, since no catalytic converter. I am still doing my Rotec highlander, but I have been toying with a potential project and this is my current first choice for an engine.

I cannot get ethanol free auto gas.
Dane

Paralysis by analysis
#242
av8rps
Veteran Member
Posts: 480
Joined: Thu May 12, 2011 5:01 pm

Re: Another Yamaha Re-Power Highlander is flying

Post by av8rps »

I'm really glad to see another Yamaha Highlander flying. Congrats! I too dislike the Rotax cost, and the complexity. So it is great to have another option.

But I do feel obligated to defend the Rotax. My Highlander with a Rotax 912uls has similar performance numbers to what you posted for the Yamaha. But to be fair, I'm using a 21 inch 8.50 tire and an open tube gear, and you have what looks like large 29 or 31 inch bushwheels with a covered gear. My Highlander is also under 700 lbs empty, so maybe yours is heavier to start with? Also, the performance numbers I'm using for comparison were taken on a very nice early fall day here in Wisconsin at aaproximately 75 degrees f and at an elevation around 1300 msl, so depending on your flying conditions maybe that too could be skewing numbers between our planes? Also, my engine has less than 300 hours since new vs 1700+ hrs on your 912. And not sure how props would compare, but I'm still running a 2 blade 70 inch Sensenich prop, wheras you indicated a much larger diameter, more STOL oriented prop on your Rotax.

Again, I don't mean to diminish anything about your Yamaha install as I think it is a cool retrofit option. And the gobs of power it makes is for sure impressive. But if a 912uls is set up right on these planes they should do about what you are getting. I suspect however that the more you become familiar with your Yamaha set up that you will see much better numbers, as the thrust numbers alone that Steve has shared with us were pretty crazy.
User avatar
marl59
Seasoned Member
Posts: 84
Joined: Thu Oct 22, 2015 5:59 pm
Location: Oakland, CA

Re: Another Yamaha Re-Power Highlander is flying

Post by marl59 »

Have to leave so this’ll be quick. The Luga does have metal leading edges but they’re on about the outer 1/3. I set my Luga prop at +3 today and was cruising at 110 mph. It would never reach that speed with my old setup. I’m sure I could exceed Vne if I set the prop to +4 or 5. But I am only interested in STOL performance. Wife is looking at me like it’s time to leave. More later.
AV8R Paul
Veteran Member
Posts: 578
Joined: Sun Mar 22, 2015 7:49 pm
Location: Garland, Texas

Re: Another Yamaha Re-Power Highlander is flying

Post by AV8R Paul »

Very nice looking install! I would have put a speed bump on the cowl to hide the exhaust. However, kind of aesthetically cool looking.
AV8R Paul
Certified Light Sport Repairman LSRM-A
Copro
New Member
Posts: 12
Joined: Mon Dec 05, 2016 3:54 pm

Re: Another Yamaha Re-Power Highlander is flying

Post by Copro »

Sweet........
User avatar
marl59
Seasoned Member
Posts: 84
Joined: Thu Oct 22, 2015 5:59 pm
Location: Oakland, CA

Re: Another Yamaha Re-Power Highlander is flying

Post by marl59 »

Re: Another Yamaha Re-Power Highlander is flying

Postby Clark in AZ » Fri Mar 09, 2018 12:03 pm
Awesome! Thanks for taking the time to do a write up. Really impressive numbers. Be sure to report back as you get more time on it. Any troubles with it so far? Any unanticipated problems with the install or running of it?

Clark,
I did have a problem with the first RK400 clutch that I got from AirTech in Alabama. The material that was used on the clutch pads was inferior. The pads only lasted 10 hours! Fortunately they quit hooking up with the prop during my taxi back to my hangar! However I reported my results to the owner and he asked me to send the pads back to him. He will send me out a new set of pads with the superior material on them. There are 2 materials that these clutches come with. The one you don't want looks like a weave with peaks and valleys, this one smells terrible and spits black, sticky gunk out. If you get a clutch with this stuff, please don't install it. I assume this was designed for a very low horsepower application. The other, superior pad material looks like the material you would see on a drum brake. I purchased a set of pads from TMR in Canada with the good material on them and they work great. I don't anticipate any problems with these. Ive been experimenting with different prop setting and I'll be able to give some updated climb/cruise numbers soon.
Clark in AZ
Veteran Member
Posts: 356
Joined: Wed Oct 07, 2015 11:40 am
Location: Cave Creek, AZ

Re: Another Yamaha Re-Power Highlander is flying

Post by Clark in AZ »

WOW! Glad you got that figured out on the ground. Thanks for reporting the problem with the pads. Can't wait for the updated flying results...

Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
moving2time
Veteran Member
Posts: 243
Joined: Fri Oct 15, 2010 5:42 pm

Re: Another Yamaha Re-Power Highlander is flying

Post by moving2time »

Marl59 & Copro, Steve had problems starting his RX1 without the slipper clutch. Sounds like at least one of you have the slipper clutch. Have either of you had problems starting your RX1 and what kind of temperatures have you been starting and flying so far? Does the RX1 start reasonably well in the cold? How cold have you started the RX1? One thing I hope to accomplish with building and flying a Yamaha powered Highlander will be to fly it constantly. Sounds like both of you are logging some serious flying time. Congratulations. Clearly an incentive for me. Joe B
Post Reply

Return to “Just Aircraft”