I have been told the Rotax 912 is/isc has had some nagging problems

[SSCBD]

Hi all.

 

I have been told and getting the feeling the Rotax 912 is/isc has had some nagging problems. Have noted by comments from guys in flying schools (lessons cancelled or changed general knitting circle talk) that their training aircraft is down due engine problems (they did not know what it was and I did not ask and not referring to airframe problems), but is seems to be fairly frequent over the last 7 months or so. Not major failures that cause rebuilds. I know these aircraft can do a lot of hours over a month or so but still gremlins are not fun.

 

My Question is WHAT are the common gremlin’s that the 912 is / isc have. Compared to the 912 ul carb version which uses more fuel ( say 3 lt hour yes ) but seems to be a better performer for reliability long term.

 

I would suspect most are electrical based but will stand corrected.

 

Can we get a list of problems you have had with hours run on engine and what was done to fix the problem? Including costs or replacement parts.

 

I am looking to get a Rotax 912 this year end depending on what is really going on with the problems and what spares to carry if I go the 912 is / isc route.

 

 

[SDQDI]

We have a local club member with one in a Bristel which has spent a little time grounded BUT from what I have heard the problem was with the constant speed prop and not so much the engine and going on what I have heard a lot of people with the same constant speed prop have had the same problems.

 

From what I have seen I would go the is version especially now since it has been out for a little while. I do remember hearing of some electrical problems early on but I haven't heard anything lately.

 

 

[Toby1]

Rotax 912 Series Engine Operation & Maintenance Concerns: An Interview With Brian Meyerhofer of Leading Edge Air Foils | Midwest Flyer – General Aviation Magazine

 

This site has some information that may be of interest to you

 

 

[storchy neil]

read and weep what in the hell have I been saying how about sending that to tech neil

 

 

[SDQDI]

That is an informative site Toby but is talking about the 912uls not the 912is which was the op's original question. Having said that it nearly deserves a thread of its own and I don't mean to sound as if it is not a valuable post.

 

 

[skeptic36]

I have the 912I.S sport, I had one instance where the efis told me it was burning almost double the fuel it should have been, I landed, checked everything, changed nothing, took off again and all was good. I have had to install a larger fuel filter and clean the screen in the fuel pressure regulator, since this work was completed it has been a little difficult to start if it hasn't run for a while, It behaves like it is getting a bit of air into the fuel system. Currently there is a service bulletin out, to change the stators, I will take it to Floods to have this work carried out and get them to plug in their magic "dongle" to see what the high fuel burn issue was and get them to look into the starting issue. The only other problem I have heard is, contacts on top of the motor can come loose and require extra cable ties to keep them in place.

 

For some reason there seems to be a few people that want to tell me I'm going to have problems, one guy is certain the gearbox is going to crap itself, and another proclaims that the ones in his area have " all sorts of problems" but so far has not been able to give a single specific example.

 

Mine only has 130 hrs.

 

 

[Downunder]

SSCBD, The rotax-owner site is good for info. ($45 subscription)

 

There is a forum section and an "is" section within this.

 

Any questions are quickly answered by people like Roger Lee, who is pretty much a world renowned expert.

 

An education/maintenance video section is available too.

 

 

[RJ601]

I have the 912I.S sport, I had one instance where the efis told me it was burning almost double the fuel it should have been, I landed, checked everything, changed nothing, took off again and all was good. I have had to install a larger fuel filter and clean the screen in the fuel pressure regulator, since this work was completed it has been a little difficult to start if it hasn't run for a while, It behaves like it is getting a bit of air into the fuel system. Currently there is a service bulletin out, to change the stators, I will take it to Floods to have this work carried out and get them to plug in their magic "dongle" to see what the high fuel burn issue was and get them to look into the starting issue. The only other problem I have heard is, contacts on top of the motor can come loose and require extra cable ties to keep them in place.For some reason there seems to be a few people that want to tell me I'm going to have problems, one guy is certain the gearbox is going to crap itself, and another proclaims that the ones in his area have " all sorts of problems" but so far has not been able to give a single specific example.

Mine only has 130 hrs.

912iS Factory fitted engine in a new Aircraft 2015

 

Hi My new engine has now done about 100 hours. 130 landings majority in my paddock strips (Extra vibrations) & no prodlems

 

1/ The 4 electrical sensor connectors on the top Air box must be kept really tight as per the Rotax fix for this problem. If not you will get the Lane A light coming on. I had this happen a number of times prior to the fix

 

2/ Make sure you get the starting sequence correct. 1/4 Throttle. Toggle switch down - Wait until both lights go off - While keeping toggle switch down use other finger to press the starter button - After starting I keep the toggle switch down for about 10 Sec at about 2200 RPM.

 

3/ I recently had fuel problems. Make sure you keep the Accumulator filter clean. Have it checked regularly especially after a new build (Small contaminants can be lodged in tank / tanks) Same for in line Rotax filter. My LAME did a full fuel flow. If I remember correctly 10L / 7Min after filters changed running the fuel into a container from a point after the in line Rotax filter with 1 tank valve closed. I always use a Mr Funnel as the fuel systems must be kept extremely clean.The engine is Now running better the best since I've had it.

 

Quicker take off roll. Better climb. Smoother cruise. 15 - 16- LPH

 

I'm yet to get stator done.

 

Good luck I am really impressed with my 912iS

 

Cheers RJ

 

 

[greybeard]

The 'nagging problems' isn't just a couple of the members of this forum posting their usual is it?

 

 

[JohnStrong]

We have an iS in our Bristell NG5.

 

The only issues we have had are sensor failure indications due to poor connection under vibration as mentioned above. Fixed with tie wraps.

 

Also had the Stator SB done without any drama.

 

Overall we are very pleased with the engine, starts immediately, smooth and reliable.

 

We have about 70 hours on it so far.

 

John

 

 

[facthunter]

Engine complaints are only allowed if it's a Jabiru. Just joking, people. The "fit and forget" engine doesn't exist. If you don't give them the right attention they will get your attention. Information sites that are properly researched and supervised are invaluable. You should also have them for individual self build planes and for any types really especially as they get older to keep up with inspections/servicing/ repairs latest mods etc. Intending buyers get the information that helps them make the right decision and know there's support after they purchase it. Nev

 

 

[Admin]

Engine complaints are only allowed if it's a Jabiru. Just joking

Nev, the Moderators are now removing any unwarranted digs against Jabiru engines now

 

 

[pbugg]

I've done 570 hours. Only nagging problem is lane drop out which is fixed by cleaning the outside air temp probe connection which is disconnected to remove cowl. I have had two EGT probed fail. No problems, engine starts and runs great and fuel economy is unbelievable. I get 10 lph at 120 knt cruise, 16 lph gives me over 135 knt. I have also replaced the standard Woodcomp prop for a MT CSU and very happy

 

 

[Kyle Communications]

There are 2 912IS engines here at YCAB that I know of that both have had electrical problems. Bad connectors in the wiring...engines would not start. Took a while to nail them down...both in different harnesses too