Why I have always hated Rotax

[Abid]

All I can tell you is my last gyro, a two place Dominator... With the second ever Yamaha to bolted to a gyro... the 3 cylinder carburetor version... won the Groen brothers international time to climb contest, and successfully flew with power to spare, a pilot and passenger weighing a combined 550-570 lbs and that was on a hot day in Florida. I recently flew with Greg in his AR1 with a 914 rotax and it did not seem to have the same power as I remember my dominator having.

I really like the torque curve of the 3 cylinder engine. I have had 3 different Yamaha street bikes that use more or less the same versions of these sled engines that people are converting. A Yamaha FZ07 ( 2 cylinder 700cc) a Yamaha FZ09 ( 3 cylinder 900cc ) and a FZ1 ( 4 cylinder 1000cc ) The 09 is the best engine of the bunch, combining the torque of a twin cylinder engine, but the high rpm pull of the four cylinder. The four cylinder was for sure much more powerful, but it needed high rpms to get that power where the 3 cylinder was punchy and had a stronger pull at much lower rpms. I still have the FZ07, as it was my favorite bike out of the 3 overall, but the 3 cylinder 900 was the best engine of the bunch.

But saying that, if I were to convert a sled engine today it would be the four cylinder with Teals adapter and likely his gearbox as well.

As I am sure you could source all the parts and convert one for less than 6-10 grand, but I think most people will end up with at least that 6-10 grand into the project once you factor in everything such as exhaust system, motor mounts, cooling system, instrumentation, etc... etc... etc...

Dominator is a light gyro. AR-1 is at least 120 pounds heavier than a Dominator
Apples and Oranges. Better comparison is Tango and AR-1
Teal's gearbox mates I think to the Apex without any adapter btw.
Trust me if the Yamaha used sled motor is too high a price conversion, people buying them won't pay for it. The way it works generally is that it is 1/4 of the price of a Rotax of similar capability. I tried offering Yamaha conversion on AR-1. Was willing to do all the work but was not going to just put a used crash sled engine right out. I wanted it rebuilt. The price that came out was $10k lower than a 914UL and despite that people who wanted Yamaha in an AR-1 did not go for it. Simple. They are looking to save mucho $$. I don't blame them but I am not doing a conversion with a crashed sled motor as is. I have been sued before in a fatal accident lawsuit. If I had a used converted car engine or similar in that aircraft, I would have been done. The only people who offer such things turn key are the ones who have not been around in aviation business long enough to be sued yet and actually survive through that ridiculous experience. I don't mind someone buying and doing their own used crash sled motor conversion as long as it's not in the invoice we provide.

 

[GyroRon]

Dominator is a light gyro. AR-1 is at least 120 pounds heavier than a Dominator
Apples and Oranges. Better comparison is Tango and AR-1
Teal's gearbox mates I think to the Apex without any adapter btw.
Trust me if the Yamaha used sled motor is too high a price conversion, people buying them won't pay for it. The way it works generally is that it is 1/4 of the price of a Rotax of similar capability. I tried offering Yamaha conversion on AR-1. Was willing to do all the work but was not going to just put a used crash sled engine right out. I wanted it rebuilt. The price that came out was $10k lower than a 914UL and despite that people who wanted Yamaha in an AR-1 did not go for it. Simple. They are looking to save mucho $$. I don't blame them but I am not doing a conversion with a crashed sled motor as is. I have been sued before in a fatal accident lawsuit. If I had a used converted car engine or similar in that aircraft, I would have been done. The only people who offer such things turn key are the ones who have not been around in aviation business long enough to be sued yet and actually survive through that ridiculous experience. I don't mind someone buying and doing their own used crash sled motor conversion as long as it's not in the invoice we provide.

Well a couple of things...

1. I believe that some of the sled engines come from crashed sleds, but not all of them. Mine didn't. Mine came from a perfectly functional used low mile sled. Bought the sled, pulled the engine and wiring, and sold the remains of the sled as parts to help offset what was spent on getting the engine.

2. Back before the euro style gyros became so popular, a decent two place gyro was maybe 30 grand, 40 grand tops. Hard to do a 30-40 grand gyro when you're using a 20-30 grand Rotax engine. That is why converted Subaru and Honda and Mazda auto engines were so popular... That is also why you saw people looking at Webers then Yamaha. The thought that there would be people willing to buy gyroplanes that cost 75-125 thousand dollars was silly... Gyroplane people were always thrifty, always looking for ways to achieve whatever it was they wanted at a minimal cost.

I guess we were wrong about it though... Because there was apparently a strong market of people that DID want a gyro but didn't want something that was built from raw materials via plans or some kind of rudimentary kit with a junkyard Subaru car engine on the back... These people wanted something that was more or less factory built ( and face it, almost all the euro gyros are factory built with minimal to do for the " Builder " to have to do other than write a big check ) and looks all sleek and fast and smooth. And they are willing to spend big money for it. And if they are spending 100 grand to buy the thing, at that point why save 10 grand for a used converted snowmobile engine...? These people are not strangers to aviation. They see the popularity of light sport aviation, they see that the Rotax is used on most everything so they want a Rotax too.

The Tango uses the Yamaha, because Tango is unique amongst the euro gyro brands.... They have that euro gyro look, but they aren't as polished, they look cheaper and they are cheaper... and by using converted sled engines they can be even cheaper. Their gyros are perfect for the person that wants a euro gyro at the lowest cost, but with each Magni, AR1, and Autogyro purchase made, its clear that there are people out there that want what they want price not being a factor. Alot of words to simply say that I am not surprised that people didn't want to save 10 grand by going with a Yamaha on your gyros.

 

[NoWingsAttached]

Did I mention...

Back when Rotax stood up and took notice that we three combined Yamaha conversion folks, Todd Reick, Greg Mills and Teal Jenkins, were SERIOUSLY cutting into Rotax 912/914 engine sales, and realized that Todd and Teal were doing it using Rotax C gearboxes exclusively for their conversion kits, Rotax at first required a 582 engine serial number to order a new PSRU, and when that didn't stem the tide of Yamaha conversions using these PSRUs Rotax decided to quit making the C box altogether, and did so quite abruptly.

Greg Mills was the first person to discover and report this, and wrote about it here on Rotaryforum. The usual rotten tomatoes got thrown at Greg, he got called an asshole publicly and awarded the Mr. Sour Grapes medal of doggy doo-doo for the umpteenth time, but regardless of what you may think of him and for whatever reason you do, the reported end to all Rotax C gearboxes was in fact realized as claimed.

The Rotax C sold for $1625 delivered, on a good day previously.

The "E" box is exactly the same thing, with a little 12v starter motor hanging off the side of it. I gauran f-g T you that the little tiny starter motor on the "E" box does not cost Rotax more than $35.00, and you can buy a brand new, similar one anywhere for $50.

Let's let Rotax make a 100% profit on the starter motor, and that makes the "E" box worth $1725.00, by all generous accounts indeed.

The Canadian a-holes at Rotax sell the "E" box now for $2350.00. They upped the price of their PSRU by $725 !!! just because they added a $50 item to it.

THAT is a 1,450 % profit on that stupid little starter motor, people.

THIS is why i HATE Rotax.

 

[Smack]

Dar, you have $-numbers? Horsepower/torque numbers? Package powerplant from Teal?

 

[Abid]

Guys:
What price Rotax sells its products is completely up to Rotax. We have the right not to buy from them. Very simple.
I have recently heard that Rotax is going to stop producing Rotax 582 completely next year. That does not mean they will not sell parts or not support existing fleet anymore. Usually they will support defunct engines for up to 10 years for existing owners.

Its obvious, not enough demand is there to justify producing 582 just as it was the case for 503. I liked both those engines and have thousands of trouble free hours on them.

 

[C. Beaty]

Once upon a time when Rotax was just a hole in the wall Austrian engine builder, making scooter and bike engines, I purchased a 447 with gearbox for ~ $500. Then Canadian conglomerate Bombardier purchased Rotax and now the sky’s the limit. Bombardier’s interest was engines for their snow sleds, jet skis and the like.

 

[BEN S]

Is the 2 chlinder phazer a 4 stroke ? What is the HP range expected?
Weight with gearbox and FI systems comperable to a 582?

 

[icanflyitto]

Still a lot more proven hours logged on Rotax products for aviation use than Yamaha. For me..... reliability trumps cost. It’s my butt in the air! Flying isn’t cheap....... going cheap..... always eventually costs more.

You are going to come to love the Yamaha

 

[ultracruiser41]

You are going to come to love the Yamaha

 

[Vance]

This weekend I heard stories of several bad water pumps on the three cylinder Yamaha and a thrown rod on a fairly low time Yamaha (50 hours).

I heard stories of exhaust challenges (breakage) and some fuel delivery issues.

I listened to more stories of trouble with the Yamaha in a gyroplane than stories of success.

The highest time Yamaha powered gyroplane that I heard of was less than 500 hours if I recall correctly.

In my opinion the noise they make with a very heavy muffler is loud and annoying. I find myself looking for a way to turn down the treble and turn up the base. The shrill sound they make carries a long way. I could hear all of the Yamaha powered gyroplanes at Anahuac from several miles away. I even heard the sound of the Yamaha powered gyroplane the over the sound of gyroplane I was flying powered with Rotax 915 as I was climbing out.

In my opinion if I did pattern work with a Yamaha powered gyroplane at most of the airports where I fly there would be noise complaints and I would either have to make it quieter or find an airport in a less populated area.

From my motorcycle background I learned that noise is a way to make enemies of the non-motorcycle people and there were more of them then us.

It is even more so with gyroplanes so I hope people with find a way to quiet the Yamahas down before gyroplanes start getting banned from noise sensitive airports. Based on my experience it won’t just be Yamaha powered gyroplanes that are banned just as it wasn’t just loud Harleys that were banned.

 

[XXavier]

Rotax engines are horribly expensive, but getting any spare part is fast and easy (if also expensive...). The availability of spare parts is a good thing, and it comes at a price, as often happens with good things...

 

[GyroRon]

Yall a bunch of haters!!!!

Let's see.... Rotax got its beginnings in aviation cause some folks took it upon themselves to try using some of their two stroke sled engines in ultralight airplanes.

Not much different than what some are doing today, by pulling Yamaha sled engines and converting them to be used in light sport aircraft.

Only difference is that 20-30 or however many years ago, Rotax saw what people were doing and decided maybe they could make some money offering their engines for sale as aircraft engines.... so they made improvements and offered gear reduction boxes etc.... Yamaha hasn't done that.... At least not yet.

Sure if you took a given airframe, say a Magni airframe... And you could power it with a Rotax 912 or 914, OR.... A converted Yamaha sled engine, Chances are the Rotax would likely be the more reliable choice. It has now, decades of use behind it, and most all of the flaws have been identified and addressed. That will take time with the Yamaha engines.

But either engine can fail. And rotax engines DO fail. Plenty of cases of that happening, even today.

There is a substantial difference in cost between the engines. That is part of the appeal. That has always been the appeal with " alternative engines " .... That is why benson gyros used Mac drone engines instead of Cont C65's off piper cubs, That is why RAF and Sparrowhawk gyros and slews of homebuilts used Subaru car engines instead of Lycoming O-290 or 0-320 engines. And it is why even to this day people are willing and wanting to use car engines, boat engines, jet ski engines, Snowmobile engines, motorcycle engines, lawnmower engines, etc.... instead of purpose built aviation engines.

Even the Helicycle uses a converted engine.... A Turbine conversion from a generator

I personally think the Yamaha is a good engine as far as a core engine. What will make it or break it as far as a aviation engine is how well it was converted and how good the reduction drive is.

There are now hundreds of Yamaha engines flying, Way more in airplanes than gyros. If your on facebook there are facebook pages for Yamaha conversions and just going through the postings, doesn't seem to be too many people having trouble out of them. Teal Jenkins has made getting a reduction drive easy and he has made conversion products for these engines that rival anything Yamaha or Rotax or any other big name firm would have come out with.

Vance, your claims about the exhaust being loud is silly talk. There are loud exhausts on all types of engines. I have heard annoying exhaust on Macs, Subarus, Lycomings, and even 912 series Rotax. A properly designed and muffled exhaust can be fitted to any of these engines. Reality is these yamaha engines are sled based, and also motorcycle and side by side ATV based. If you have the chance to hear the exhaust on the sleds, or the Yamaha street bikes or SXS these engines are based on, they are VERY quiet. But sure they can be made to be very loud with a straight through glass pack exhaust. With the right exhaust on them though, they are not loud.

 

[C. Beaty]

I don’t want you guys picking on my friend Vance: -please bear in mind that he fell off a motorcycle going 300 mph and left half his brains smeared out along a mile of California dry lake bed.
In retrospect, the expression: “fell off a motorcycle” sounds a bit denigrating, more accurately; he lost control of a motorcycle streamliner while attempting to set a world speed record.

 

[Smack]

Has Vance achieved "sacred cow" status ?

 

[Vance]

Vance, your claims about the exhaust being loud is silly talk. There are loud exhausts on all types of engines. I have heard annoying exhaust on Macs, Subarus, Lycomings, and even 912 series Rotax. A properly designed and muffled exhaust can be fitted to any of these engines. Reality is these yamaha engines are sled based, and also motorcycle and side by side ATV based. If you have the chance to hear the exhaust on the sleds, or the Yamaha street bikes or SXS these engines are based on, they are VERY quiet. But sure they can be made to be very loud with a straight through glass pack exhaust. With the right exhaust on them though, they are not loud.

The exhaust on the Tango is both loud and annoying Ron.

Several people at the event commented on how loud the Tangos were.

The Yamaha is not as bad as a Mac without a muffler.

A Tango would be quickly banned at the San Luis Obispo airport if someone was training with it there.

They have detailed noise procedures and I have been called out for not following them when the tower asked me to make an early right turn.

When I call the Santa Maria Public Airport (formerly known as the Santa Maria Army Airfield built during World War II for training P38s) they have a phone line just for noise complaints.

Every couple of years we have to work to get aviation friendly people on the Airport Board.

Several on the board would like to close the airport and noise mitigation is a part of why they ran for the airport board.

Developers are always after the dirt and the property values would go up if the airport noise was gone.

A gyroplane doing pattern work is particular annoying because it is low, slow and comes around often.

Noise has been the excuse for the demise of many airports.

I have an effective muffler on The Predator.

I have no doubt I could build a quiet exhaust for the Yamaha.

So far quiet does not seem to be a priority for Yamaha powered gyroplanes.

As I recall yours was quite loud.

 

[GyroRon]

My yamaha powered gyro, when first put together, I used a 20$ straight through glass pack muffler I picked up at Tractor supply company, that was meant to be used on a antique Ford tractor. If anything, it was probably louder than had I just not used any type of muffler at all.

I redid my exhaust at a later date and used a straight through glass pack muffler off a Suzuki GSXR 1000 sport motorcycle. It was considerably less annoying with that muffler, but still made quite a bit of noise.

The Tango gyros typically use a similar muffler, some type of motorcycle specific, straight through glasspack muffler. Its cheap, its light, and it allows full power potential from the engine, but the negative side effect is it will be somewhat loud.

If anyone has been around sportbike motorcycles.... some call them crotch rockets, or rice rockets... With a aftermarket exhaust, this is essentially the same thing, as the Yamaha engines are very similar to the engines in the sport bikes and with the same exhaust, they are just as loud if not louder since the engine is up above you ( if being observed from the ground )



But it is UNFAIR to judge yamaha engines as bad engines because some builders have chosen to use a straight through exhaust. This would be like me saying all Lycoming O-320 engines are bad engines because the lycomings on Vans RV series airplanes are quite loud. Well sure they are loud on a RV-4 because its a straight pipe exhaust with no muffler at all. The Lycoming O-320 on a Cessna 172 or Piper Cherokee isn't anywhere nearly as loud, because it uses a actual muffler.

If noise is a concern, then you must design and use a effective muffler system for whatever engine your flying.

And I will agree, that excessive noise IS a problem in general. We see the same issue in motorcycling, where some places we like to ride our dirtbikes is being lost because neighbors are sick of the noise.

 

[wolfy]

One of the reasons I was considering a two blade prop was because of noise, not that they are actually quieter but just that they have a lower tone that could be less annoying than a three blade pusher prop.

wolfy

 

[Vance]

I wasn't going to chime in again on this post cuz I am tired of the point - counter point arguments and disagreements. It gets to be a bore!
That being said I am trying out an exhaust that is from a sport bike (Suzuki GSXR 1000) first and a Verex muffler second that it is tunable for sound profiles from loud to quite. So noise is not the issue for my Yamaha! The same can't be said about the noise often written in text form that is just as annoying to me in that regard. https://xforceusa.com/product/vmk15-250/

I have no intention of entering into a debate about how suitable a Yamaha engine is for gyroplanes.

I feel they are not perfect and there is still work to do.

The Rotax is not perfect either.

One of the noisiest gyroplanes I have encountered had a Rotax 912 with straight pipes.

The Sport Copter II I trained Doug in was very loud with her Lycoming IO-360.

There was also an ELA at the event that was pleasantly quiet and several people commented on how nice that was.

It is a wonderful challenge to make something that is not intended for aviation suitable for aviation.

We are operating in the real world and I feel there is value in being considerate.

 

[GyroRon]

I feel that the yamaha is a perfectly suitable engine for conversion purposes.

Any engine can have problems

And any engine can be made to be loud or quiet ( within reason, hard to make the engine in a Harrier Jump jet quiet )

It would be up to the builder to decide if noise reduction is important to him or her or not. For a lot of people it isn't much of a consideration. But it is a worthwhile goal to try to make it as quiet as practical.