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Turning world
   A few words in
Defense of the 582 Rotax
This Page was created
 Sept 10, 2oo1
UpDated Sept 1st 2oo2



My experience with the 582 is that it is a very very poor engine I have had 5 of them and 4 of the 5 have had big end rod failures at 200 hours.  I'm very experienced with 2 stroke engines I have been in Rotax power for 13 years and am a considerate operator also I keep my maintenance up.  Rotax makes some good power but they just don't give it to the airplane guys.  I don't understand that but that's the way it is. I have an A model Avid Flyer and a Model 4 Kitfox.  If I stay with 2
stroke power which I don't think I'm going to I will use the 100hp Hirth.

Talk to ya later

Jerry Sharp

Rotax Tips from Sweden
September 2oo1

I found an interesting note regarding the 582  at


The jet needle and clip should be inspected on a regular basis for wear.
Wear occurs in the area where the clip rides. Failure of the clip and or needle will cause the needle to:

A) lower itself causing a LEANER fuel mixture or
B) the needle will fall down into the bottom of the carb causing loss of power.
C) cause erratic engine performance as the needle bounces up and down

It is important that the sieve be in place and not damaged. This is not a filter or screen. It's purpose is to convert foam back into fuel. During rough operations the fuel in your float bowl with foam. When you pass foam through a screen it turns back into fuel. With the sieve in
place over the main jet of your carb no foam can form causing misfiring etc.

There you find a little better explanation on the "foam" problem in carburetors that make a lean mixture. So, the meaning is that the 582 must have a high degree of maintenance and not be left to live on it's own for a longer period and have weared or cracked parts.

The ultralight homepage is a very good source and seem to have good reliable information.

Best Regards from Sweden


It seems the Rotax 582 may be getting an unwarranted bad rap in the past year or so. Yes, a 2 cycle motor of any manufacture is possibly not as reliable as a four cycle motor, but remember a 2 cycle is not as expensive or heavy. You get what you pay for. If you want a high power to weight ratio and or do not want to spend much money, you use a 2 cycle power plant.
You may or may not know that the 582 is presently standard equipment in a purposely un-named helicopter that seems to be having lots of vibration problems. These un controlled vibration problem may easily have caused the 582 to quit and thus the accident cause being blamed on the power plant, not the helicopter.
I personally know of one person who's crank shaft counter weight came off his 582 and if  I remember correctly,  another person who's lower end  bearings disintegrate due to excess vibrations from this craft.
This one helicopter is known to have been delivered with a heavy centrifugal clutch that was out of dynamic balance from the factory. This same craft has a cog belt drive which produces a high frequency puls/buzz feeling in the frame. A cog belt is generally not recommended to be used on a two cycle motor do to the fact that a cog belt easily transfers (due to the rubber teeth/cogs) the 1 power pulse per revolution X the number of cylinders  in the engine. It is said using one or more multi V, V belt allows the pulse to be absorbed and not transferred into the frame/transmission/free wheeling clutch.

This same craft that seems to be single handily ruining the past good reputation of the 582 also uses a un rubber isolated belt tightening roller on the primary drive. This roller is hard mounted to the frame after permanently tensioning the drive belt between the out put shaft and the transmission which also transmits the high frequency vibrations directly into the frame and remember, the engine is also mounted to the frame.

Anyway, please remember, the 582 has had a good reputation before being slated as standard equipment in this one troubled helicopter. The manufacture of  the experimental helicopter that I purchased and fly (CH-7 Angel) chose to use the 582 along with it's original designer, Augusto Cicare. There are now (I believe)  a little over 1oo CH-7 Angers flying all around the world using the 582 with no where the problems this other craft is having. So, it just may seems that it may vary well NOT be the Rotax, but the vibrating bird it is mounted in.

Yes, a helicopter's demands are different than a fixed wing air craft's, as I pointed out above, it is working for others helicopter manufactures, but just not this one manufacture.

Anyway, That's My 2 cents on the 582 Rotax but hell, I could easily be wrong.
What is yours on the 582 Rotax.
eM SHnPGIE your experience w/the 582
Oh, I almost forgot a problem I had w/my Rotax. At around 16 total hours of operation, 12 hours of flight. I needed to replace the rotary valve seal in my 582. Turns out I used a to high a pressure cap on my cooling system and blew out the seal due to excess pressure one hot day.

Rotax 582, Mini 5oo n the CH-7 Angel

The CH-7 has not experienced the same problems that the Mini-500 has despite their common
lineage and powerplant.

Well, I'm curious myself. Are there enough hours on the CH-6/7 and as many out there to give an
accurate comparison?

 Hello,  Mr Extreme

Yes, there are enough hours on the CH7 Angel fleet. Helisport have flown more than 3000
hours. And over 2000 hours have been reached by the CH7 fleet in Europe. The most interesting
thing however is that there was reported not a single forced landing due to engine seize of the
 Rotax 582.

Only to your information: I' m myself a proud owner of a CH7, I' m going to become an
aerospace engineer and I' m a professional helicopter pilot within German Army Aviation

Based on this figures there can be no doubt, that IT IS NOT THE PROBLEM of ROTAX (!!!).

But it would be a little too short to say that the seize of an engine is no engine problem at all - of
course it is.

1st    The first question is: Propper cooling at a propper power setting.

2nd    The next question is: Minimized vibrations caused by the engine and the power

When you take a closer look at these points once on the Mini500 and once on the CH7 you (as a
non engineer) will only see minor differences. But these differences are essential.

A friend of mine installed some baggage compartment under the fuselage of his CH7. During
flight test he saw  very soon, that the flow of colling air to the radiators was insufficient - he
returned before the engine quit and modified his compartment.

Some months later he saw the construcion of Elisport - and he was astonished - it looked very
much alike as his (In engineering one would call this a form follows funcion method :-) ) I only
coose this example to tell you, that similar proplems demand similar or even the same

As everyone in this newsgroup has now seen, the operation RPM differ between the Mini500
and the CH7. An other fact is, that the output power in the flight-manuals of Mr. Fettner were not
measured in the propper way. (I just wonder if there is really no owner of a Mini500 on this
planet who did it in the right way ????)

The next point is, that there is a cooling problem under the cowling of a Mini500. (I would
simply use a smoke generator to see the flow of air through the radiators in all stages of flight -
of course a wind tunnel simulation/testing might be the best way) But besides these eningeering
failures, there are others, too. One is a lack in structural safety - or in other words a
underdimensioned fuselage. This in combination with the vibrationlevel caused by power
generation/transmission and... produces a high level of material fatigue.  A friend of mine
experienced this after a forced landing with a Mini (Take a look at his hompage:  )

An other one is the joint between the landing gear and the main fuselage. On the CH7 the
bending forces of the landing gear are NOT transmitted into the main-fuselage. When you look
at the Mini500: The skids are stiffly fixed to the mainframe....

My personal opinion: ALL these points in their combination are the reason of the mishap of the
Mini and all involved people.

If you want a safe helicopter it's no use to solve only one of these critical points - one has to
solve them all (!).

And here is the real problem:
         Every engineer knows this
         Every sales-person knows this (but won't tell it)
         Every owner wants to ignore it - because the amount of money needed is high.
         Every one who takes a closer look will see that the best way will be to take all the parts
         of the powerplant out of the kit and buy the fuselage, powertransmission and exterior of a

Before all off you stone me: Please take a close look on to the facts. If you don't trust my
arguments especially about the structural safety - CALL a professional engineer that is familiar
with finite-element-methods on leightweight structures (NASTRAN,Pro/E,....). And then - do
whatever is needed to achieve safety.

I hope all of you will advance in solving the whole problem.

With kind regards from Bavaria,  Robert

 Robert W. Wittmann
 mail to:
 University of The German Armed Forces
 -  Aerospace Engineering -
 German Army Aviation

582 Rotax's Oil throttle adjustment

I have always hesitated to write the below few paragraphs for a number of different reasons. But perhaps the below could help one person some place one day... ALSO, I now realize as many of you know,  seems lots of people hesitate to share there ideas n findings on their helicopters (also using the 582) between them self's due to the manufacture's unique business style (sadly I now refer to him as "the helicopter Hitler")...... And perhaps the below is common knowledge, if so sorry, I personally had to find it out the hard way Perhaps the reason  is only because I am not and never have been much of a the mechanical type of guy.

For some un known reason, the Rotax 582 and ONLY this unmentionable helicopter seem to not be comparable. My helicopter (the CH-7 Angel) along with at least 135 more of  it's brothers n sisters uses the SAME engine with NO problems. To date, the only fatality that I know of  in the Angel was when a Italian pilot took off into the evening sun and a set of wires.......

However, even thoe the CH-7 Angel uses the same power plant, the manufacture of the helicopter (NOT the Rotax manufacture) recommends adjusting the oil throttle differently than the Rotax manufacture recommends.......

Now, I stress that the below Is NOT the way the Rotax operators manual recommends adjusting the 582's oil throttle. And the foto below is almost the way I have Miss Nina's throttle adjusted, which is ALSO NOT the way the CH-7 Angel manufacture recommends......

You may have noticed how an Angel smokes when it is started from being cold. Miss Nina's Oil Throttle SettingMy little Miss Nina does..... The Rotex company recommends adjusting the oil throttle so when the engine throttle is closed the oil throttle lever is at the left most mark (see below). The Angel's manufacture recommends the throttle be aligned at the right most mark (hard to C in this foto) when the throttle is closed......

Not liking how Nina's EGT were always close to the red line and almost always touching the red in a decent, no matter how I jetted, I decided to re adjust against what the engine manufacture suggested and try what the air frame manufacture suggested.... Well after doing so, my EGTs were lots better, but my plug checks were scary. Nina's plugs were all gummy and agents All what I had been taught about reading spark plugs and what you should be looking for...... But still the EGT were great......
Than it dawned on me....... I decided to do a plug check with out a cool down...  I flew Miss Nina, landed quickly and Switched off the engine WithOut a cool down period. Seems to reason the low RPM of the cool down period of 2 min. would be giving me plug readings of the cool down period, Not the true readings from flight...... Any way to make a long story, I ended up compromising and not adding quite as much oil as the helicopter mfr. suggested. I now have Nina set almost exactly in-between the two marks according to plug readings I was looking for. However, with the same setting after a cool down period, still look scary, on the virge of fowling. But when visually inspecting the plugs with out the 2 minute cool down, all 4 plugs looked good n the EGTs were always in the green arch, even in a shallow decent w/power.

As I stated above, this is NOT the way both the Rotax n the RPM helicopter company recommend  you set your oil throttle on your XYZ 5oo helicopter..... But I use the same engine and it seems to work better this way..... But I could be wrong, don't wanta get sewed for causing your plugs to foul on your XYZ 5oo helicopter..... I just can't stand hearing about people continually getting killed and hurt.....

Glenn Ryerson, Host/WebSter @ SHnPGIE

Disclaimer.... Remember, all the above is from a guy that sells ice cream for a living, that just knowing how to use a computer....... NOT from a helicopter mechanic in any stretch of the imagination....... However, this is the EXACT oil throttle setting on my helicopter's 582....

Comments from  one of the news groups on the 582
Are there any XYZ helicopter 5oo owners that can give me any feed back on the XYZ expensive expantion chamber kit offered by the XYZ helicopter manufacture?
The XYZ helicopter (as provided) will not tolerate being tuned to anything near "performance specs.  The carbs (as provided) are junk, there are wild harmonics that this engine is trying to live under, its a wonder that it lives at 1100 degrees.
All of  the manufacture's charts are on a dyno without float bowl foaming and at 1250 degrees.  If  he were to dyno the expansion chamber of the pipe at 1000 to 1100 degrees which is the max EGT that the pipe and carb combination he supplies will live at you will find the HP is nowhere near advertised.
Save your money and buy a good set of pamper crabs and get the engine to live at 1200 to 1250 where it should be run at.  Then the rotax will really be putting out the claimed 65 HP with the stock pipe which is probably all the expensive expansion chamber is putting out at the band aid temps that it is running at in real life.  Show me someone who is running the expensive expansion chamber at 1200 degrees with the BING carbs and and I'll show you a seized engine.
In a snowmobile this engine happily lives at 1200 to 1330 degrees with no problems, BUT it has good carbs that do not allow BSFC's to go below safe levels.  DO NOT BUY THE expensive expansion chamber unless you are first going to get the engine to work and live at levels that it would work at in any other application or you are simply masking far greater problems, float bowl foaming, harmonics and junk un-tunable carbs.
The 582 Rotax is a good engine, the expensive expansion chamber may be a good pipe, BUT NOT WITH THESE CARBS AND NOT WITH THE VIBRATIONS IT HAS TO LIVE UNDER!!!
XYZ, a  XYZ helicopter owner
South of the Equator

Special Note
On the Above
In the above article on the defense of the Rotax, Please change the part where it says ...dyno the expansion chamber pipe at 1000 to 1100 degrees ... to read 800 to 900 degrees...

Is seems that the maximum that this engine seems to live at with this pipe is UNDER 900 degrees, and since Gils accident I'm not sure that is even accurate.

I'd hate to have someone read this page and set their egt too high. The point is even more clear any ways!

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