Yamaha Genesis 120hp engine

Friendly

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The clutch used is an RK 400 clutch used on rotax 2 strokes for the exact same reason we use it on a Yamaha. The clutch is designed to replace the stock flywheel and rubber donut in a Rotax C gearbox. The part attached to the crank (clutch shoe holder) has been redesigned by Todd to match up to the Yamaha crank. The clutch shoes and Gearbox side of the clutch is the stock unit provided by Air-Tech. Attached is a link to the clutch at Air-Tech.

http://www.air-techinc.com/catlist.asp?categoryID=atclutch&typ=Exclusives

Jason
The reason, I asked about the factory clutch weight is because , Rototech has said that my Weber will need a flywheel. I was trying to get an ideal of how much weight the original clutch was .
 

Jason O

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Clutch weight

Clutch weight

I never ran the Yamaha without something bolted to the end of the crank. My gut feeling is that it would run fine. If you add the "C" box without the clutch and no propeller, I am sure it would run fine. Things get interesting when you add the propeller. Testing an engine without the propeller will tell you nothing more than you are getting spark and fuel, it is not a predictor of a sucessful conversion. I dont know how much the original clutch weighed, but I also believe it does not matter in the application of turning a propeller through a gearbox. In my opinion, you should start with a 12lb flywheel that is as large in diameter as you conversion will stand and with as much of the weight towards the outside of the flywheel as possible. The flywheel must be mounted inbetween the engine and gearbox. If you are successfully able to spin a propeller through out the engines opperating range with acceptable vibration levels, then you could try removing some weight from the flywheel.

My $.02 worth
Jason

The reason, I asked about the factory clutch weight is because , Rototech has said that my Weber will need a flywheel. I was trying to get an ideal of how much weight the original clutch was .
 

Russ Hobbs

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Thank you very much, I really do appreciate your letting me know.

Russ
 

kmccune

N701DZ someday!
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Any thing new happening with this engine? The economy kinda cut into my building for the last two years, but things are looking up,so I hope to get back to it soon.

Kevin
 

kmccune

N701DZ someday!
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Did you friend use the Yamaha?

Kevin

Randy, I have a close friend of mine building a Zenith CH-701 and he is going to be using one of these Yamaha motors as well in his plane. He is in the building process as well and is a long way off from his motor install as well.
If you get done before him please post pictures of your install and if he gets done before you I will do the same for you.
Yes, of course. You can call me anytime you like.
Todd
 

Racer

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Nothing really new happining on this motor, we like it the way it is so I think we should stay with what is working.

Yes my friend is using the Yamaha 120hp motor. He is mounting it now.
 

kmccune

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Thanks!
Is there a way to contact your friend, for details, to avoid more off topic posts? Though, I have to say that you guys seem very tolerant of me posting my fixed wing questions here, I do appreciate it.

Kevin
 

Monarchist

MTO Sport Owner
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Hi Todd...do you know anything about Larry Neal's Monarch gyro? I'm in the middle of a build and looking for 912 alternatives.

It's fun re-reading this thread back from 2008!

Thanks!
 

GyroDoug

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Hi Todd...do you know anything about Larry Neal's Monarch gyro? I'm in the middle of a build and looking for 912 alternatives.
Thanks!

John,

Do you have a Monarch Kit? or an Aurora kit? I was thinking you had an Aurora but in your question to Todd you mention the Monarch kit. The reason I ask is because the Monarch kit is not designed for a Rotax 912 or any 912 alternative engine. I believe the heaviest and most powerful engine that airframe is designed for is a Rotax 582.

If you have an Aurora kit, your airframe was designed for a 912 and 100 HP. The Yamaha engine Todd sells is a little heavier than the 912 and a little more powerful but I believe the airframe could handle it. When Todd first started doing these conversions I got really excited about this option and talked to Larry about putting one of these on my machine. Larry Neal is a very conservative guy who's number one priority is looking out for the safety record of his machines and because of that he is simply not interested in using anything but engines designed specifically for aircraft. As a Dealer for Larry, I needed to make my machine (which will be a demo machine used to show the world what a Butterfly is like) needed to be built with a factory approved engine so I gave up on the idea of using a Yamaha sled engine. However, I suspect that Larry would be open to the idea of you putting one on your machine as long as it is designed to handle the loads.

I don't know if he would feel like there needs to be any changes to the Aurora airframe to handle this engine or not, but he is the expert on these machines and I would strongly recommend that you follow his recomendations, regardless of whether they fit the plan you have currently figured out to get you into the air. I suspect this will be a good option for you but understand anytime you make major changes (like the powerplant) to an aircraft, it ususally entails a lot more, that you could originally see and plan for. As long as you go into the project understanding that, you should be fine. Best of luck with this and let us know what you end up deciding.
 

Monarchist

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I should have said Aurora...that's what I'm building. When I first ordered it, there was only the Monarch, the 912 was an optional engine. I don't know what else is different between the Monarch and Aurora.

I would love to see how the mounting works for the Yamaha...I think it'd be a hell of a good engine choice.

-John
 

bandit

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Genesis for fixed wing Highlander or Kitfox

Genesis for fixed wing Highlander or Kitfox

Sorry to intrude on your rotary forum. I am trying to find out if anyone is developing any fixed wing Genesis installs? I have seen the amazing work and R and D that Racer has done and I must commend him on not only Stellar workmanship, but also to make it work so well! Great Job Racer! I wish you had time (and the interest) to apply all of your skills to a fixed wing application. I am sure you would have many many interested people!

Thanks
Bandit
 

Racer

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Thanks for the nice comments Bandit.
Yes there are at least as many fixed wing installs as gyro installs so there is somebody who is probably doing or done whatever you may be interested in.
Keep your eyes open because more and more of them are getting out there all the time.
Todd aka Racer
 

HobbyCAD

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Hervey Bay, QLD, Australia
Oil Reservoir Positioning

Oil Reservoir Positioning

Any comments out there, regarding the placement of an external oil reservoir for use on the Yamaha 4-strokes? I want to make my own, the original looks a bit "out of place". How low can I place it? How high can I place it? I suppose the lower position is determined by not requiring the pump to "lift" too high. What determines the upper position? What should the volume be? The manual says there is just shy of 4L in the complete system, and the tank should be filled with 2L, if drained.

Regarding the cooling system, does it need a radiator cap that releases excess expanded water pressure into a reservoir, that sucks it back in if it cools down? What other options are there?
 

Hawk

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Hi All,

I thought it a good time to inject another Yamaha transplant! This is the MH1 upgrade for the old Mini. We are using the Genesis 120 carby motor. The yellow ship is one that I am building at the present. All the mechanicals are completed and in process of modding the cooling system per installation and then on to the electrical. This ship will be ready for testing in the coming months.
I have rebuilt the engine. It was purchased from Ebay with no good history and with the required updates from Yamaha it was the prudent action. With what I found upon disassembly and inspection, I would recommend that all donor engines be gone through. As in the case of John from Millennium found out (pics attached of his engine)! I'm in process of rebuilding his engine also. I will be rebuilding my engine before I install in my ship. The rotating assembles in both engines were in good shape, the problems are with the valve train/drives. Though the root problem being in improper jetting in the case of Johns engine and I will assume some from poor maintenance of its past life in a snowmobile.
HobbyCad, There is no ,lets say guide lines, to the placement of the oil tank. The best is to keep it as close to the engine as feasible and for ease of access to the tank. Yes you have to have a radiator pressure cap and a coolant recovery tank for the system to work at its proper efficiency.

Cheers,
Rick
 

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