Why do people hate "Rotax" engines?

[Seth]

I know the Rotax engine is considered a lawnmower engine by some, and that it's not a Lycoming or Continental, which are based on as many have said, 1950s technology, but really, why is it that there is so much hate toward the rotax?  Have there been more failures in flight proportionally than the Lycoming or Continental, more problems?

 

Just curious - I haven't searched all over and read articles, so I'm looking for honest opinions, but with a caveat that if it is an opinion, please mark it as so, vs fact, which I'd also love to have "marked."

 

Separately, from a technical sense, why do some say that a two stroke engine is a death trap vs a four stroke?  If a cylinder blows, a cylinder blows and usually the engine is useless after that (opinion) in most cases.  I know the P-47 could fly with a Jug missing and I personally had a cylinder dying on me once and as long as I kept the power down, the cylinder stayed cool enough to get to an airport - had the cylinder lost completely, I would have had to put the plan down right there.

 

Thanks,

 

-Seth

[Mooneymite]

The Rotax 4 stroke (912/914) engines are well regarded in the experimental/LSA worlds.  Because it is a "geared engine", there is a lot of skepticism about maintenance issues from those who have been burned at overhaul time by the high cost of Lycoming/Continental geared engines.

 

The older 2 stroke Rotaxes did have some reliability issues in aircraft.

 

Of course, the Rotaxes sound very different from the slower turning legacy engines.

[N601RX]

I've flew about 200hrs behind a Rotax 2 stroke and never had a single problem with it. It was one of the later model water cooled ones. There were some Rotax specific things that you need to keep a check on, like any engine. The air cooled ones had more problems. 

[scottfromiowa]

I have no issue with them personally. I won't ever own one as they don't fit my mission for a cross-country mission. When I can no longer fly my Mooney I will hang up my spurs...or fly Citabria's with an instructor to get my aviation fix. When I think Rotax I think of the para-pusher (ultra lights)...and I think light and NOT as crash-worthy as my certified plane. For those that love them. Good for you. I am just not a fan/user/interested party.

[Chimpanzee]

Hmm,

don't all those Katanas that schools like CAE use have Rotaxes ? They should know a thing about them.

Cheers
N

[carusoam]

People don't hate Rotax as much as they just prefer more powerful engines...

Rotax, SkiDoo, SeaDoo, CanAm, LearJet and Challenger jets, are all part of Bombardier. A large North American conglomerate.

When comparing a two cycle small engine to a four cycle Lycoming, the end user considers buying a new Rotax at @ 1000hrs compared to OH of the standard @2000 hrs.

Whatever fits your finances and expectations, as an individual.

The newer four cycle engines have worked well with the two seat market.

I prefer to extend the OH period to 20 years. Having to top or OH every five years would add to the challenge of private aviation....

It does make for an enjoyable debate considering all of the technology they have included with their offerings.

My thoughts,

-a-

[Yetti]

I found it interesting that Rotax were powering the Predator Drones

[Bennett]

I had a Rotax 912 engine in my DOVA LSA. Absolutely dependable, (once we found a bad crimp in the wiring harness). Started on the first blade, and stopped immediately. Took me a while to get used to the tach at 5500 ROM, but the engine was smooth and the right amount of power for this LSA. I did have to manually turn the prop a few turns to "burp" the oil into the engine, but it always worked. Quirky, but a decent engine.

[sufferingcadet]

I thought some rotax engines weren't certified for IFR flight plus if you use too much 100LL it changes the maintenance requirements because the engine can't tolerate lead as well.  Car gas is cheap but the problem is it's not available at most airports so it really diminishes the utility of the plane for cross country. 

[AmigOne]

When the moment comes I would have no hesitation about flying behind a Rotax with double ignition.  They are so popular that I was surprised by the original question of why do people hate Rotax.  

[Guest]

A Rotax engine is generally a reliable engine, just very expensive. A good overhaul will cost you as much as overhauling a four cylinder Lycoming. They burn virtually no oil between changes, auto leaning, fuel efficient, are simple to maintain but are lower powered, great for trainers or LSA.

Clarence

[David Mazer]

I have a 914 and, to me, its cost seems diproportional to its power compared to other engines.  A new Lycoming with 125 hp costs a lot less than the $32,000 starting price for a 914.  The new Honda variant (the Viking engine) is 110 hp for about $20,000.  I've been forced into an overhaul right now and would have changed engines if I was confident in the retro fit for an engine mount in the plane (a SeaRey).  The TBO is now 2000 hrs so that isn't a factor anymore.

[bumper]

Before considering the Honda Viking variant, one would be wise to do a search on Jan Eggenfellner. Looks to be more'n a few unhappy scammed customers out there.

 

bumper

[DaV8or]

A Rotax engine is generally a reliable engine, just very expensive. A good overhaul will cost you as much as overhauling a four cylinder Lycoming. They burn virtually no oil between changes, auto leaning, fuel efficient, are simple to maintain but are lower powered, great for trainers or LSA.

Clarence

 

Why is that considered expensive? A four cylinder engine is a four cylinder engine. Why should one expect it to be cheaper just because of displacement, or HP output?

[DaV8or]

I have a 914 and, to me, its cost seems diproportional to its power compared to other engines.  A new Lycoming with 125 hp costs a lot less than the $32,000 starting price for a 914.  The new Honda variant (the Viking engine) is 110 hp for about $20,000.  I've been forced into an overhaul right now and would have changed engines if I was confident in the retro fit for an engine mount in the plane (a SeaRey).  The TBO is now 2000 hrs so that isn't a factor anymore.

 

Is Honda officially selling a piston aviation engine, or is this just some after market conversion?

[Guest]

Dave,

Aside from the high initial price for the engine(dollars per horse power) replacement parts like pistons, cylinders, and carburetors are very expensive.

Clarence

[David Mazer]

The Honda engine is not an aviation engine.  It is a conversion but I've heard it is a marine rather than automotive engine.

[Lood]

The Rotax just don't sound real, man!

And although some old WW fighters also sported these, I am NOT a fan of a water cooled airplane engine.

[N601RX]

Rotax fits a certain segment on the market very well. It produces the same horsepower as the O-200 and has an installed weight of about 100 lbs less than an 0-200.  With a plane that has a usefull load of around 500 lbs that is huge. Its also has a smaller footprint and fits the lines of the small planes better.  It gets its power from high compression pistons and higher rpm. Jabiru also makes a nice engine.  The other popular options for these small experimentals is the William Wynn Covair Conversion and Great Planes VW conversion.  Both have been around for a long time and have the bugs worked out.

[scottfromiowa]

VW...bugs worked out...good one.

[N601RX]

There have been many companies open up with the promise of a great auto conversion.  Most all of these have long since went out of business, many taking customers deposits with them.  One of these was mentioned several post above.  Both Wynn Corvairs and Great Planes VW stayed with it and worked through the problems. They both have a very good rep.  They offer a low cost alternative engine that many people are flying with. 

 

http://www.greatplainsas.com/whydiff.html

 

http://www.flycorvair.com/products.html

[bd32322]

I have flown behind one in fort collins, colorado, and with auto lean, it was great. It fits its mission of puttering around at the base of the rockies. Just dont try to outclimb them. I generally had a positive impression of them.

The only subjective negative I can mention is that when pulling back power, it is not as smooth as a lyc/continental. Dunno why that is the case or whether it was due to the airframe/prop combo. And by not smooth, I mean I was wondering if something was wrong.