Yamaha Genesis 120hp engine

flyboat.no said:
Hello Todd

What is your experience about vibration, noise etc, Yamaha vs Rotax 912/914.

Erik
Norway
Click to expand...

The Yamaha engine does not vibrate at all if there is no load on it but as soon as you put a gear reduction and prop on it then it does vibrate pretty good when cold up to about 2,000 RPM then it smooths out like glass. My hanger mate has a Rotax 912 and his motor does the same thing.
I am installing a centrifugal clutch on mine and I think that will solve the vibration problem.
As far as noise in the sled it is very quiet but the stock muffler weighs like 12 pounds and some change... very heavy. If you do not have any muffler on it at all it is very loud, I am trying to find a happy medium where it is not very loud but I want to do it without carrying that heavy muffler.
https://www.youtube.com/watch?v=mBrVMqy7q4A

All in all a few small issues to work out but nothing that cannot be easily solved.
 
Is it possible on the 80 and 140 hp engines for the internal gear ratios to be changed enough to allow the PTO shaft to be at a usable rpm for a "direct" drive prop?
 
hi racer ...i have just receved my yamaha 120 from a savge yard and it looks ok but it is dirty and i have seen yours and rons and they look bran new so i would like to know what you used on them and how you cleand them ...and if any one elts has any idea's feel free to chime in ...any help getting rid of the black spots would be great ...thank's
dennis
 
To Dilly (above)

Helpful Hint:
Spray Diesel onto surface- (optionally...scrub with plastic brush) hose down with warm water, pressure airhose to dry. Purchasing ready made degreasers works too.
 
Have not been ignoring you guys, I have been busy working in the shop.

Big Ben, I am sorry, I cannot answer your question as of yet, I do not have one of these motors in my possession.

Dilly, Ron's engine had under 300 miles on it, did not have any cleaning that needed done.
I do not have any method as to how I clean stuff, sometimes it is with solvent but that is only for parts that are off the machine. https://www.rotaryforum.com/forum/showthread.php?t=19983&highlight=Engine+cleaning This thread may help though.
 
You got me David, everyone David has a great buy on a snowbird. I've been trying to sale my horse trailer to a friend but he's having trouble. So If your interested in a nice machine give David a call. David offered me a sweet deal.
 
thanks Minnesota_Mike and racer for the help ill try some of the metheds ...have you guy's tryed using baking soda with a sand blasting set up ..my buddy use to clean his atv motor with that and he said it worked great
 
hi racer i got a chance to talk to my buddy about the 80 hp yamaha i have and he said whants it so im going to hold on to it for him ....but if he changes his mind ill let you know...thank's for the intrest
 
Todd- You are really making a name for yourself! It really takes people like you with ingenuity to make things possible for others. My Helicycle kit would only be a dream if it werent for people like you making things happen. Stan
 
Stan,
Everything you do is a step above top notch, Your helicycle build is seriously a work of art and your craftsmanship and attention to detail is truly second to none. You have set the bar high for the rest of us and I can only hope to come close to your work.
Your projects are truly an example of the quality that I am shooting for. thank you for showing us how things should be done.
Thank you for the compliment, coming from you that carries a lot of weight.
 
Todd- IMHO, you are overselling what i am doing, and underselling what you have contributed. I am doing nothing more than mimicking what I see on my build videos supplied by the factory. Sure, I feel I am doing a good job, but its not like they are dumping a turbine engine in my lap, and saying, "here, you figure out the engine mounts, turning some tranny parts, and with no instructions. Your type of work isnt having your hand held, its using your head and your machinists skills that I wish I knew. You would laugh at some of my struggles working with metal instead of wood. Anyway , I feel you dont really realize how much people like you contribute to making all the machines this world has. Enough said! Stan
 
Stan, It's no secret Todd and I are friends, but I'll agree with your assessment, Todd and I talk about idea's, and Todd magically produces them. I am in awe of his abilities to convert idea to matter.
 
Here are some pictures of a motor mount for the 120 Yamaha that I recently shipped. This motor mount is for a fixed wing ELSA airplane so it had to be very different from the other mounts I fabricated.

The reason it had to be so different is because this mount has to attach to the existing bed mount locations and also has to be totally self supporting because I have no mast to attach the fifth attachment point like I do in Gyro applications.

I hope that the owner of this setup will share some photo's of the complete install with us soon, I believe he will even though this one will not be on a gyro.

PS. No I am not interested in building any more of these, this was a lot of work and took much more time than what I actually charged for.

Yamaha Genesis 120hp engine


Yamaha Genesis 120hp engine


Yamaha Genesis 120hp engine


Yamaha Genesis 120hp engine
 
Last edited:
lanichol said:
Exactly. Amazing work. How did you get those bends?
Click to expand...

Did the bends by hand using only a hand pump hydraulic press. One thing with Aluminum you only get one chance to get it rite, You can bend it but if you go to far you cannot bend it back. If you do you just took a lot of the strength out of the part.
 
You must log in or register to reply here.

Similar threads

RogerB
Edge Performance Engines and Engine Kits
Replies
16
Views
2K
Mayfield
Mayfield
A
Rotary engine for rotary wing
Replies
0
Views
272
arg948
A
gyroplanes
Rotax 914 oil magnet plug question
Replies
6
Views
935
gyroplanes
gyroplanes
M
Avionized BMW engine.... is this the right time??
Replies
9
Views
1K
nishanh
nishanh
P
Rotax 914 Servo Motor to TCU wiring
Replies
6
Views
915
Pete2512
P
Top