Collection of Rotax Forum Feeds

[Newshound]

Ran across this site / vendor selling kits that add manual mixture adjustment and automatic mixture adjustment kits for 912's.

In principle, and per their claim, if you can fine tune mixture for for optimal actual conditions you should get better performance, better fuel efficiency, etc.

www.greenskyadventures.com/bing/HACmanFAQ.htm#4

www.greenskyadventures.com/bing/HACmanorder.htm

They show on some engines on their site some documentation of improved fuel efficency, etc.

If their claims are even approximately true it would not take many hours for one of these kits to pay for itself in fuel savings.

Curious if anyone has, or knows of, any experiences with these kits, or comments/thoughts.

If I understand right owners of standard category aircraft with 912's probably could not legally use these kits, but us owners of experimental and amature builts could.

Any thoughts?

Al

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[Newshound]

A prominant difference we as Rotax flier experience with Rotax 4 cycle compared to pilots in many conventional aircraft is

(a) we don't have carb heat deal with, yet don't seem to have carb icing issues

( we don't have mixture controls to adjust for altitude.

I think I understand "a" (but any education on that welcome anyway.)

But don't understand how a CV carb is automatically adjusting mixture for altitude changes.

Anyone know of a good explaintion article or animation or video on how CV carbs adjust mixtue for altitude? I found some videos on youtube on CV carbs but they really didn't cover how altitude/mixture compensation occurs (either that or it just went over or under my brain ).

Also curious how well the automatic mixture adjustment works compared to a hopefully-properly-operated traditional manual-mixture-adjustment system on, say, lycomings?

(I see that at least one vendor sells a aftermarket mixture control system add-on for the 912,

and curious about that, but will post that in a separate post here.)

Al

(

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[Newshound]

Just curious:

Anyone have any idea (or even real numbers) about how many total 912s have been manufactured?

Date they were first produced?

Whether most or all of them are/were in aircraft?

How many are still out there running?

How those numbers compare to numbers of Lycomings out there?

Just wondering.

I know they are in use in dozens of models of aircraft,

and even a few in military unmanned aircraft.

Al

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[Newshound]

Hello Gentleman,

Happy to report that my previous issues have been solved thanks to the assistance I have received mostly from this forum.

Now I have another one that I wish for assistnce,

There is an overflow reservoir atttached to the radiator but I never see it doing anything, Today on the ground and tied, I was running the engine to make sure I am getting the proper RPM, The cooling temperature did reached 200 degrees, I slowed the engine down to reduce the heat and shut it down, I was under the impression that the hot coolant from the radiator to overflow into the reservoir but it did not and never have seen it do so, Is that an issue that I should be concerned about? normal flights and normal ground & extented rolls temperature stay within the envelove, thermostat new recomented tepm, cooling system had been flashed as I thought it wasn't circulating, I have removed the cup before it gets real hot to checked the radiator and I seen the coolant circulating,

Any input on the matter will be appreciated,

Regards to all

Yanis

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[Newshound]

Goodbye Rotax... Sorry to say the Rotax was not a pleasant experience for me. Had my 912S for almost 6 years. First 2-3 years OK. Then problems began. Hard to start mostly. Also difficulty with magnetic plug, 3 voltage regulators, required tubing changes. Consulted with several Rotax 'experts' about starting problem, followed almost all suggestions. Overhauled carbs, new plugs, idle adjustment, bigger battery, battery charging. You name it I tried it. Never installed recommened larger cable between battery & starter though. Couldn't install larger starter due to space constaints. Saved the most expensive item for last, replacing the ignition module. Ask prominent Rotax facility about testing the ignition module. Their reply, No testing apparatus exists. Hard to believe in this age of plug-in devices for automobiles. So for almost $1200 a new ignition module seemed to do the trick. Once I got it started I got rid of it. Last year of ownership I considered the engine totally unreliable. No x-c's for fear of getting stranded. Rotax service spotty at best, and almost noone suggested the problem may be the module. With an aircraft that won't start, mechanics reluctant to leave their home airport to assist left me frustrated to say the least. I know it's probably unfair to compare the Rotax to an automobile engine but when my Saturn and Mercury always start for a total of 17 years, with hardly any service other than oil and spark plug changes, it's easy to say Rotax is lacking in design and reliability. Just look at the myriad of problems reported on this website. An the constant flow of problems found by Rotax that must be fixed ASAP. My flying experience of 65 years in all kinds of aircraft and engines reflects superior reliability except for my 250 hours with the Rotax. For you reading this tale of woe, I wish you a good experience with your engine. Sorry to say, my expectations were not met. I will continue to fly as much as I can, but with a more reliable engine up front. Thanks for your time reading this.

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[Newshound]

Just an FYI for those who don't know and I hope this helps some day,

There have been many numbers thrown around for the Rotax starting required rpm. We don't have magnetos we have trigger coils. In order for these to get excited and fire current to the plugs we need a minimum of 225-250 engine rpm which translates to 92-103 rpm using our 2.43:1 gearbox ratio. Now if your battery is weak and you only get 85 prop rpm or less it won't start. You can not tell the difference looking at the prop or listening between the 93 to 85. So if your aircraft doesn't start you need to use a newer battery or jump it to rule out the possibility of a poor battery.

We have 5 trigger coils. 4 for our needed amps/voltage and one for the tach signal.

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[Newshound]

I've a Rotax 582 Mod99 (Blue headed) engine with about 280 hours. I'm having overheating problems: At 5500 rpm the water temperature goes up to 80ºC(176F) with the outside temperature (air) about 28ºC (82.4F).

The water temperature usually stabilizes at about 75ºC(167F) at 5100 rpm and goes to 80°C at 5500rpm.

I've checked:

- cooling liquid (anti-freeze 40% water 60%)

- fuel octane / fuel mixture

- cooling ducts

- instruments or sender (tested with termometer out side the motor)

- thermostat (tested with termometer out side the motor)

- changed spark plug

- changed air filter

- changed jet needle and needle jet

- airscrew turn 1 (one turn)

What else can I do ?

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[Newshound]

Hi,

Iam owner of rotax 582 UL DCDI Mod.99 blue head.

How to ajust the 2 cylider tembrechures the same, CHT and especially EGT.

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[Newshound]

I was encouraged by Rotax techs to install a backup electric fuel pump and a soft-start module to my engine, even though it started just fine on the first try every time. Added the pump. But now it does one of three things: With the electric pump running, and choke on, it will start right away, run fine for a few seconds, and then quit. Or, with or without pump running, but choke on, it will turn over once or twice and then kind of cough and stutter to a stop. (After either of thse it will usually start normally the second try.) Finally, with just the choke on and no pump it may turn over and then stop, or it may start up normally and run normally. Engine is cold and OAT in the 30's. After warming up it starts just fine. Any suggestions? I'm particularly concerned about it turning over a few times and then stopping, even though the key is still set to "Start".

Bill N.

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[Newshound]

HI ALL

Still having trouble, oil in intercooler, loosing 200ml per hour, flushed all the oil lines

out, no luck, seems to happen during flight . Could it be going past the seal in the turbo.

Local rotax expert assures me that not likely. Checked the oil return back to the tank ,plenty of oil flow.

Run out of ideas

Greg Regan

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[Newshound]

I have a 912ULS in my aircraft and I love it. It is smooth through the power range and sips fuel. For the past few months it developed an annoying habit of sometimes having "lumpy" running when I reduce the power through 3500 rpm on base/finals. Above that setting it's fine and below 3000 it's also fine. It probably has only done this one in ten times and because of the intermittence, I haven't been able to work out what has caused it. Carb syncing always shows the carbs are nicely balanced and nothing obvious has ever shown up until this morning...

After a 4 hour trip yesterday I decided to have the top cowl off and give her a good look over. This was also because the engine lumpiness happened again on the last approach of the day yesterday.

I could see that one of the throttle cables (behind the splitter unit) had been pulled through more into the engine bay than it should have been and was stuck there with the cable sheath pressed tight against the grommet in the firewall hole. I can only assume that this was probably a result of one of the starts I had yesterday being quite "hard". It appeared that the engine movement on start up has sometimes been dragging the cable through and it has then been catching on the firewall hole and hasn't been able to return behind the firewall, leaving a throttle cable kink between the firewall and the carb where it should just be a striaght run. But surely if the cable hasn't stretched then there will be no affect you ask???

What was interesting is that when I gently touched the section of cable that had been pulled through, it released back and found its proper place, taking tension off the cable. At the same time, I watched the point where the cable joins the carb' arm and it must have released back about 3mm. Not a lot, but certainly enought to temporarily de-sync the carbs in the lower/mid range power setting I would have thought.

I am guessing this problem has been intermittent and "self-curing" as when it happens it doesn't take much to get the cable to ping back to its normal position and I am guessing that this has been happening automatically each time until now on the odd occassion the rough running has been present. ie it has been self-curing.

Just thought it was worth mentioning as I, like many, assumed it was something to do with jetting, atmospheric changes as the OATs warm up etc etc.

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[Newshound]

I checked the gearbox clutch friction and had written to torque the bolt (not the locking bolt) to 22 ft-lbs on notes I took during your Video. When I checked the Rotax Line Manual, it gave a torque of 15 Nm, which would be about 11 ft-lbs. What is the correct torque for this bolt? Thanks

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[Steve Sliwa]

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[TD][h=2]BRP/Rotax Rolls Out New Engine[/h][TABLE=width: 200, align: right]

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Rotax has added a new engine to its line of popular four-cylinder, four-stroke aircraft engines—the 912iS. The new engine represents somewhat of a technological leap for aircraft powerplants in that it features direct fuel injection and an electronic engine management unit. Company officials rolled out the new engine at BRP/Rotax's company headquarters in Gunskirchen, Austria on Thursday morning. The launch customer for the new engine will be Pipistrel Aircraft, an LSA and soon-to-be manufactuer of certified aircraft located in Slovenia. BRP clearly intends the 912iS to be a "green" engine with improved fuel economy and lower emissions as one of its design goals.

Horsepower of the new engine will remain at 100, as with previous models of the 912, but in place of the Bing carburetors, which some owners have complained about having to adjust from time to time, the 912iS will have automotive type fuel injection with an ECU capable of timing and shaping each fuel charge. Each cylinder will have dual injectors for redundancy. BRP claims up to 30 percent lower consumption than like-power aircraft engines.

The overall physical size will remain essentially the same as previous models of the 912, although the weight will be about 6 kilograms more for a total weight of about 63 kg or 140 pounds dry, installed weight. The engine will also have an external alternator to both power the ECU and ship's systems. BRP says the engine will be available in two versions, the 912iS non-certified and the 912iSc for certified aircraft. Production is scheduled for March 2012 and the engine will come out of the box with a 2000-hour TBO. AVweb will have a full video report on the engine later this week.

The engine will run on autogas up to E10.

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[Newshound]

The cat is out of the bag!

Fuel Injection for the Rotax. You should be able to see one at Oshkosh.

Pipistrel Newsletter:

ROTAX, a name that is synonymous with light aircraft, LSA aircraft and even military drones and in a co-operation with Pipistrel today marks a very important milestone in the history for ROTAX with the release of the new fuel injected 912 IS aircraft engine.

This new engine the ROTAX 912 IS produces 100 hp from what is basically the same engine core as the 912 ULS with the exception that the carburettors are gone, now replaced with modern fuel injection. This relieves the engine from carburettor imbalance and provides perfect start-up/shutdown and idle just like a modern car. The choke has gone and the engine responsiveness has been increased substantially along with an approximate 10% reduction in fuel consumption at normal cruising speeds.

As the world's leading supplier of aircraft engines for Ultralight and LSA aircraft, ROTAX aircraft engines have truly revolutionized the aircraft industry. The popularity of these engines continues to soar higher and higher, from the original two-stroke engines through to the modern four stroke engines ROTAX produce an engine for just about every aviation application and many hundreds of non-aviation applications.

The 4-stroke 4-cylinder boxer engines we are now familiar with and known as the ROTAX 912 series started development in 1984 having advanced technology and superior weight/performance ratio and have propelled experimental, Ultralight, LSA aircraft and motorgliders for many years gaining themselves an enviable reputation for reliability, low noise, fuel efficiency and most important actually reaching the TBO times. ROTAX aircraft engines are available in two configurations including fully certified engines as well as noncertified engines; both are very similar and enjoy a fantastic reputation.

Today is a significant milestone for both Pipistrel and ROTAX with the release of the 912 IS engine, ROTAX have chosen Pipistrel as the 912 IS release customer and the engine has been fitted and tested on the award-winning Pipistrel Virus SW aircraft. Those that have flown the aircraft report increased smoothness, faster throttle response, lower idle and most importantly for the environment less fuel consumption for this exciting new engine. Now a little history lesson. 1920 The company was founded in Dresden, Germany as ROTAX-WERK AG. 1930 Taken over by Fichtel & Sachs AG, the company transfers its operations to Schweinfurt/Germany. 1943 The company’s operations are relocated to Wels, Austria.1947 The company’s operations get relocated to Gunskirchen near Wels.1959 This year sees LOHNERWERKE GmbH of Vienna acquiring a majority shareholding. 1962 For the first time, a ROTAX engine is installed in a Ski-Doo snowmobile developed by bombardier. 1970 This year sees integration of Bombardier and ROTAX. The former Bombardier Inc. branch BRP, now an independent company, uses ROTAX engines in its motorcycles, personal water craft, and snowmobiles. 1977 High orders of snowmobile spare engines ROTAX® 185, 248, 284, 294 are also used in Ultralight aircraft. 1978 Ultralight engines 501, 505 developed (based on snowmobile engine 503). 1982 The company begins development of ROTAX 4-stroke aircraft engines, a landmark in ROTAX history.1983 The company starts producing ROTAX motorcycle engines for APRILIA. 1984 Start of sales of ROTAX 912 engines. 1988 The company starts producing ROTAX marine engines for Bombardier Sea-Doo watercraft. 1989 Type certificate for ROTAX 912A. 1993 The company starts producing ROTAX motorcycle engines for BMW, Germany. 1994 Type certificate for ROTAX 912F. 1996 Type certificate for ROTAX 914F. 1998 Type certificate for ROTAX 912S. 1998 The company starts producing ROTAX engines for Bombardier ATVs. 2000 The company begins initiation of The ROTAX Quality Production System (RQPS). 2001 Launching of ROTAX 4-TEC 4-stroke engines for Sea-Doo watercraft. 2002 This year witnesses the launch of the new 2-stroke semi-direct electronic injection technology: ROTAX 2-TEC engines for Ski-Doo snowmobiles, plus the launch of the ROTAX Kart RM1 with direct drive (without chain).2003 Sale of Recreational Products Group by Bombardier Inc.; Foundation of Bombardier Recreational Products Inc. (BRP) with BRP-ROTAX as part of the new company. 2003 Approving BRP-ROTAX as International Design Organization according to JAR-21, the European Joint Aviation Authorities (JAA).2005 85th anniversary of ROTAX is celebrated and 35 years with BRP.2005 912 / 914 Series compliant to Light Sport Aircraft ASTM Standards.2006 Production of the 6 millionth ROTAX engine. 2006 582 engine compliant to Light Sport Aircraft ASTM standards. 2008 ROTAX stars manufacturing the 1125 cc Helicon liquid-cooled, four-stroke, fuel-injected 72

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[Newshound]

On my 9 year old 582 bluehead with 200 h operational time I have a very hard start after 1 month of no use. When it started there was å LOT of blue smoke comming from the exsospipe.

After some checks I figured out that the level of the rotary walveoil was 1 inch to low.

I have also had a lot of differens in my egt with up to 40 *c diff between cylinder 1 and 2.The PTO sylinder is the hottest .

At the same time the fuelpressure on max 7 - 8 psi which is too high.

Which sealing can cauce theese problems ? Or what else could it be ?

Torstein

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[Newshound]

It seems,from previous discussions on this exercise.

This can be a problematic.

Is there any reason why fitting a washer would create

a problem.Fitting a washer would surely make life

a bit easier.

If this is not a problem what type a washer would be

suitable

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[Newshound]

912ULS, no return line, Kitfox model 5. Facet aux fuel pump in series with original mechanical pump.

MGL Xtreme EFIS newly installed with a new 0-7psi sender they recommend, so I have no historical fuel pressure information.

Here's the issue:

When I turn on my pump before engine start, my MGL EFIS shows a nice 3psi stable pressure.

When the engine is in cruise flight, it will make sudden pressure drops down to 2 PSI sometimes

even 1 PSI for a couple seconds then back up to 4 or 5psi.

Some reading in the forum here implies this may be a common situation? Is this correct?

If so, it's still disturbing, what do you recommend? Is this a 'problem' or a symptom of

my non-return-line configuration? Would adding the return line and oriface stabilize this

erratic pressure reading? OR do I have something else going on?

Thanks for your help!

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[Newshound]

Hi guys,

I need the wide dog gears in my gearbox for the turbo conversion I am doing.

As far as I know, only the 914 has these gear ??

My gearbox serial nr is 887-271. Can anyony please tell me if I have the narrow or wide gears ? And excact what parts needs to be replaced for the conversion ?

Thanks,

Thomas

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[Newshound]

I have a delema. I was checking the engine out (cold)and discovered that I had no antifreeze in the recovery bottle or the pressure tank on top of the engine.I didn't check the coolant before the last flight which had been with the winterization plates on and the engine oil temp was running 209 and CHT 250 which on the warm side (OAT 45 F) but nothing close to red line. This was just a check before heading for Sun-N-Fun. I added antifreeze to the both the pressure tank and the recovery tank and ran thye engine for about 10 minutes. On inspection I could find no evidence of a leak anywhere on the engine but I did see some dried water stains on the pressure tank below the pressure cap. The only thing I can come up with is maybe the pressure cap is not sealing properly. Has anyone run into this problem? I've ordered a new pressure cap since that is the only thing I can come up with that might cause the problem.

It would be nice to hear from anyone that may have experience a similar problem and their solution.

Thanks,

R Russ

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[Newshound]

For years automobile manufactures that use aluminum engines have recommended using conditioners in the engine coolant system to prevent leaks and lubricate the water pump as well as prevent corrosion. Bar's company makes a leak and conditioner for aluminum engines that sound like it would be benificial to use in our aluminum engines. My wifes car specifically recommends using Bar's leak in her aluminun engine.

My question is why not use this same treatment in our Rotax aluminum engines if it will help prevent leaks and corrosion?

Has anyone seen anything from Rotax regarding using a leak and corrosion additive.

Thanks,

Dick

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[Newshound]

I have a 912uls which used to develop full power on takeoff (5500rpm - 4500ft alt) and the full 5800rpm straight and level at 8000msl. I now will only develop 4800rpm on takeoff roll and in climb. After being in flight for 15+min, I will get the full 5500rpm. I have not changed prop pitch, I have rebuilt the carbs, exterior fuel filter clean, air filter clean, fuel hoses recently replaced, fuel pump inspected and found good condition, using 91 octane motor gas, engine brought up to 120 degrees before takeoff (and oil pressure 60 lbs. I have no idea as to what the problem is. Any help would be appreciated. Thanks, Jeff

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[Newshound]

Hi,

I am new to this forum, so I hope someone can help me.

I was doing a ground run static test, and had re adjusted the pitch, and was idling the engine at about 2000rpm, when the engine cut. No increase in engine speed, it was just like I had turned off both mags at once.

The engine is an early 912a with approx 1400 hours, has recently had a prop strike, and has had some work done on it by the Australian Rotax dealer.

Any ideas/ tips would be much appreciated.

Regards

Mike

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[Newshound]

Hello everyone, Bill I hope you are reading,

All my engine reading on my EIS panell are normal, A small discrepancy on Iddle between EGTs But goes away on middle and full throtle,

I notice to much fuell goes to the sparkplugs, and also notice I am using about 25% more fuell in flight,

I am afraid to start mesing up with the air screw again as I finaly am kind convinced that 1 turn on the one carb and 1 1/4 on the other one have gived me good results. What will be the item I need to check with to achieve the proper feed of fuell.

Any suggestion or advice will be appreciated.

Regards

Yanis

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[Newshound]

New problem. The weep hole on my 912 F series water pump has coolant coming out of it. My mechanic friend and I are replacing the vibration dampeners anyway, so the engine will be partially off the mounts I guess. Has anyone ever pulled a water pump and should I just order a whole pump or buy the special tools to replace the seals?

Kitfox model IV 1200

I'm all ears.

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[Newshound]

just wondering?im having a hell of a time with my 447 in my supercat,after purchace and flying home (s.a) the engine ran rough and I could only get her home by flying full throttle,after trying every thing and spending$$$$$ I bought another 447 with carbie.how ever it made No change ,runs rough at idle bogs down just after idle and rpm fluctuates at cruise and after 15 mins of cruis engine runs rough,so changed :engine(complete without exhaust)propeller,fuel system, disconected all electrics and ran engine no change so that leave 1 thing the origanal exhaust..now it has been modified the elbow join is gone and th flange on the exspasion chamber has been cut and a piece of car exhaust(10" long) slevved in and welde so its now longer and only a 2 piece...so you think this is the cause of all my grief(apperently after purchace the ex-owner fessed up and told me its always had a slight "flat spot")....the exhausst has been modified to bend under the plane in the center line.

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