Yamaha RX1 Engines

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Posted

So Im trying to get as much info as I can on these because I have always liked Yamaha engines. You guys say you get a shake at idle? Can you not just turn up the idle like every other gearbox driven aircraft engine?

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Posted (edited)

I haven't seen the "shake" myself, but am told it can be pretty rough.. 

I decided to skip that excitement / frustration and go with the TMR400 clutch from Twisted Metal Racing (Canada).  Tony there was a co-designer of the original RK400 and holds production rights.  After discussion here with Leni, and after talking with Tony, Teal, and Steve Henry I became convinced that the clutch was the way I wanted to go for a couple reasons:

1. Cold starts and uncoupled warm up with the big prop

2. Easier on everything during start and shutdown.  No shakes during startup, and the yamaha 4 strokes shut down fast and hard compared to 2 strokes that "coast down" smoother.  Both of those situations (especially the shakes) can be a little tough IMO on the rubber hardy disk, gearbox, engine mount, airframe, and any components mounted FWF.

3. The engine already has a rubber damper built into it (see pic and post above), so there is less need to have additional dampening.

4. Seaplane use of "Neutral" at idle

5. I can go up front and tell people I'm running a turboprop while freewheeling the prop by hand.  (The only reason really.... I made that other stuff up!) :lmao: 

Edited by Yamma-Fox
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Posted

Steve Henry has been running the RK400 clutch without failure other than the first (?) one due to a bearing issue.  His new Apex engine is over 150 hp, plus Nitrous.

Running and synchronizing two starters is far more weight and complexity than the clutch, with the added possibility of bind and locking up or destroying the entire system.

The starter is not strong enough to swing a propeller fast enough.  This is designed to be a SNOWMOBILE engine, not an aircraft engine.  It's designed to turn a low inertia primary clutch on a sled.  Putting a stronger motor on the starter may not solve anything if the starter drive design can't handle the torque needs, either.

 

Yes, I am coming around on the idea of the Yamaha power system.  I'm not there yet, but I am watching and learning as much as I can.  For me it means a better supply of used 912 engines on the market, which is a good thing.

I just shit myself... :lmao:

 

:BC:

 

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Posted

Steve Henry has been running the RK400 clutch without failure other than the first (?) one due to a bearing issue.  His new Apex engine is over 150 hp, plus Nitrous.

Running and synchronizing two starters is far more weight and complexity than the clutch, with the added possibility of bind and locking up or destroying the entire system.

The starter is not strong enough to swing a propeller fast enough.  This is designed to be a SNOWMOBILE engine, not an aircraft engine.  It's designed to turn a low inertia primary clutch on a sled.  Putting a stronger motor on the starter may not solve anything if the starter drive design can't handle the torque needs, either.

 

Yes, I am coming around on the idea of the Yamaha power system.  I'm not there yet, but I am watching and learning as much as I can.  For me it means a better supply of used 912 engines on the market, which is a good thing.

I just shit myself... :lmao:

 

:BC:

 

Makes a lot more sense than a Arctic Cat engine...

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Posted

I’m officially kicking myself for selling my RX-1.  :blink:

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Posted

I’m officially kicking myself for selling my RX-1.  :blink:

I really think you did the right thing!  

It looks great on the front of my plane.

:BC:

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Posted

Somehow I knew you were going to chime in. I'm glad you like it. 

 :lmao:

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Posted

the yamaha 4 strokes shut down fast and hard

That sounds an awful like your typical 912, someone needs to develop a YamaSoftStart module lol.

Seaplane friendly, yesss!

Bravo! By the time I'm ready to power up my A+ I figure you guys will have all the kinks worked out.

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Posted

Steve Henry has been running the RK400 clutch without failure other than the first (?) one due to a bearing issue.  His new Apex engine is over 150 hp, plus Nitrous.

Running and synchronizing two starters is far more weight and complexity than the clutch, with the added possibility of bind and locking up or destroying the entire system.

The starter is not strong enough to swing a propeller fast enough.  This is designed to be a SNOWMOBILE engine, not an aircraft engine.  It's designed to turn a low inertia primary clutch on a sled.  Putting a stronger motor on the starter may not solve anything if the starter drive design can't handle the torque needs, either.

 

Yes, I am coming around on the idea of the Yamaha power system.  I'm not there yet, but I am watching and learning as much as I can.  For me it means a better supply of used 912 engines on the market, which is a good thing.

I just shit myself... :lmao:

 

:BC:

 

Makes a lot more sense than a Arctic Cat engine...

douche  I meant touché  damn auto correct.  :lmao:

:BC:

 

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Posted

The C gearbox is so elusive it seems. Which ratio is best? They are hard to find 

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Posted

 

Very generally speaking,  the 3.0 ratio is preferred for the 72" sized props, 3.47 for the 79", and 2.62 for the smaller props.

Teal has a possible new lead for rebuilt c boxes, otherwise a saved ebay search will still bring a few up now and then or the E box could be adapted (see previous posts here).

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Posted

I thought Teal and another guy was making a bolt on gearbox so you guys would not have to mix match yamaha and Rotax parts. Was I reading this Wrong?

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Posted

I believe that the bolt on gearbox, was for the APEX, fuel injected motor....while the adapter, C box...was for the RX1

carbed motor. 

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Posted (edited)

Thats right, that new gearbox is for the EFI Apex motor and the RX-1 uses the C / E box.

 IMO I think the Apex will be clearly the way to go, but until it gets proven out a bit, the rx1 is the still the easiest choice as far as simplicity to convert and track record.

 

Edited by Yamma-Fox

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Posted

I am going with the RX1, for that reason. Fuel injected is here, for sure...but it will

have to be a lot more "plug and play"...before I am comfortable with it. This build

will be enough of a challenge for me...John O

Looking for the right motor to start me out...

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Posted (edited)

I am going with the RX1, for that reason. Fuel injected is here, for sure...but it will

have to be a lot more "plug and play"...before I am comfortable with it. This build

will be enough of a challenge for me...John O

Looking for the right motor to start me out...

Exactly the reasons I chose rx1!  ... all stuff I can handle.

In 3 years I'm sure I'd go apex, but I want some other pioneers to get it all figured / proven out!  LOL!

And sky4play, you on the FB group?  Make sure you contact Jim Hensel there.  He can get you an rx1 motor with all needed to run it starting at $1750 + shipping!  

There's just no way you can beat that price (if you count any value to your time in finding a sled.. tearing it apart.. selling off extras...)

Jim Hensel of Spa City Sled Parts in upstate NY.  607 329 8676

Edited by Yamma-Fox
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Posted

I gotcha

I didn't know the engines blocks were different Thanks

 

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Posted

I am going with the RX1, for that reason. Fuel injected is here, for sure...but it will

have to be a lot more "plug and play"...before I am comfortable with it. This build

will be enough of a challenge for me...John O

Looking for the right motor to start me out...

Exactly the reasons I chose rx1!  ... all stuff I can handle.

In 3 years I'm sure I'd go apex, but I want some other pioneers to get it all figured / proven out!  LOL!

And sky4play, you on the FB group?  Make sure you contact Jim Hensel there.  He can get you an rx1 motor with all needed to run it starting at $1750 + shipping!  

There's just no way you can beat that price (if you count any value to your time in finding a sled.. tearing it apart.. selling off extras...)

Jim Hensel of Spa City Sled Parts in upstate NY.  607 329 8676

Wow...great info Y-Fox...That is only a 3hr drive from me...it was in my search area...

I am not on facebook, am recently retired, so my time aint't worth what it was...:wacko:

I'll check with my girlfriend, she has facebook...and a job...John O

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Posted

John, fyi there are currently (16) EFI Apex offerings plus (7) RX-1 offerings in the Rochester and Buffalo Craigslists alone. Not including the ads placed by the guy in Ballston Spa mentioned above by Yamma-Fox.

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Posted

I have my eye on a sled that is 30 min away and under 4k miles. The gentleman that owns it,

works for the power company, and has been out of town. He is restoring power to the Noreaster victims...

Don't know when he will be home, so I have expanded my search...just in case.

I am roaring to go....Steel came yesterday...

Thanks for all the help guys....John O

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Posted

I gotcha

I didn't know the engines blocks were different Thanks

 

Yep they are very similar, and use the same mount, but that pto crankcase end housing (which is replaced with teals adapters) is slightly different between the rx1 and apex.

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Posted (edited)

I have my eye on a sled that is 30 min away and under 4k miles. The gentleman that owns it,

works for the power company, and has been out of town. He is restoring power to the Noreaster victims...

Don't know when he will be home, so I have expanded my search...just in case.

I am roaring to go....Steel came yesterday...

Thanks for all the help guys....John O

And John, maybe you already saw my bulid thread here.  It is a slow WIP, and I have been on hiatus here in the depth of winter, but I should get moving again here soon on it.

Edited by Yamma-Fox

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Posted

John, fyi there are currently (16) EFI Apex offerings plus (7) RX-1 offerings in the Rochester and Buffalo Craigslists alone. Not including the ads placed by the guy in Ballston Spa mentioned above by Yamma-Fox.

I suspect there are none here in Florida, unless they put them in personal watercraft as well as snowmobiles.

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Posted

I have my eye on a sled that is 30 min away and under 4k miles. The gentleman that owns it,

works for the power company, and has been out of town. He is restoring power to the Noreaster victims...

Don't know when he will be home, so I have expanded my search...just in case.

I am roaring to go....Steel came yesterday...

Thanks for all the help guys....John O

And John, maybe you already saw my bulid thread here.  It is a slow WIP, and I have been on hiatus here in the depth of winter, but I should get moving again here soon on it.

I have read your thread numerous times, as well as Teal's and Marshawk's great work. You guys gave me the confidence to tackle this build. Knowing there is 

help around...means everything.

Y-Fox... glad your pace has slowed...give me a chance to catch up..;)

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Posted

Hey guys. I have an RX1 engine that I pulled about a year ago. It has 900 miles on and ran fantastic when I pulled it. It's in NC, in a crate with the electrical and accessories ready for someone who wants the RX1. Shoot me a message if you want it.

Keith

keithshowalter@gmail.com

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