Hello

I am after some information please. I have a Rotax 912 ULS (S/N 5645095) that was new in 2005 and has been in an Alpi Pioneer 200 since new. It currently has 750 hrs on it (I have owned since 600). We have recently found it has been hard to turn over and after finding the thread on here regarding this we slackened off the number 2 cyl studs and sure enough it freed up indicating a fretted crankcase.

Today we removed the engine from the aircraft and have totally stripped the motor, which has confirmed fretting in several areas between the crankcase halves and there is significant wear on the white metal bearings all of which was pretty much as outlined on here and what we didn't want to see but were expecting.

What I would like to know is if Rotax provide any assistance on this issue (replacement parts etc)?? There would appear to be a serious design flaw with this older style crankcase (hence the newer design) and it seems only right that a company such as Rotax should standby there product. The rest of the engine is spotless and the pistons, liners, and crank are in fantastic condition. Its just the fretted crankcase and associated clearance loss in the crankshaft journals.

Basically I need a new crankcase, bearings, seals, bolts etc and to move everything over and I will be up and running again. Unfortunitely I am in New Zealand and parts are going to have to come ex United States. If Rotax are not standing by their product, can you please advise a good company to deal with in the United States that can provide me with the replacement parts??

Does anyone have an email address for Rotax Aircraft Engines?

Thanks,
Jonathan
  • Re: Rotax 912 ULS - Fretted CrankCase

    by » 8 years ago


    Hi Jonathan,

    You can find Rotax on line direct and you should be able to talk to your distributor which may be in Australia. I'm not 100 percent sure in your part of the world. I'm sure someone here with more info will chime in.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

  • Re: Rotax 912 ULS - Fretted CrankCase

    by » 8 years ago


    I think I may have a similar problem. My engine was new 2006. Done 400 hours. When I close down and attempt to turn over the engine there is very high friction. If i leave for 10 minutes and turn moto by the prop it seems to free up.
    I have not seen info on releasing No 2 bolts but would like some more info.
    It seems we may have others willing to take up the issue, if this my problem, and start some "class" action perhaps.
    Roy Marsden

  • Re: Rotax 912 ULS - Fretted CrankCase

    by » 8 years ago


    Hi Roy

    There is another post on this site: http://www.rotax-owner.com/forum/3-4-stroke-technical-questions/1672-hard-cranking-hot which has the information about loosening the nuts on the number 2 cylinder which are the studs which run right through the crankcase. If you slacken these off and the engine feels different and rotates easily I would suspect you have a worn crankcase like mine.

    This check is very easy to do and only takes about 5 minutes once you have the cowl off. What is the serial number of your engine?? I see the guy in the other post had serial number 5645194, and mine is serial number 5645095 which is less than 100 apart .... makes me wonder if there was a bad batch or something? Especially if yours is in that range too.

    What part of the world are you from? You are aware of other people with this issue too?? I would be all for taking some form of action against Rotax as I believe there is a serious manufacturing defect that could potentially kill someone if an engine stops at the wrong time. I will post some photos on here if I can of my engine as it is quite bad when you actually see it. Luckily we got onto this when we did as there has been enough wear in my motor on the white metal bearing shells that the oil gallerys have been warn away in the bottom of the bearing halves. In my untrained opinion I think my engine would have seized and stopped in the not to distant future.

    I have accepted the fact that I am up for a large repair bill and I have ordered a large list of parts ($5500 USD) worth from CPS to repair my motor, however I have now been told the crankcase is out of stock until April, then I have to wait for it to be sent from the US to New Zealand ... it just gets better and better!! Still at least I am alive to tell the story and rectify the situation.

    Thank you said by: YEN NIEN YU

  • Re: Rotax 912 ULS - Fretted CrankCase

    by » 8 years ago


    According to Service Bulletin SB-912-059/914-042 I think all I need is to check my engine number because the cranksaft has not been replaced and engine number does't match those which are to be checked. Also there's been a lot of talking what prosedure take to check cranksaft serial number. I assume that it need's full disassembling of the engine, there perhaps is a marked place in some part along cranksaft. I'd like to hear also more from the magnetic plug. Removal, inspection and what that magic plug does including that below 3mm it's not short. Finally, within your video's is only still picture by the plane pattern with sound :huh: attleast in my computer ( problem between chair & net) :woohoo:

  • Re: Rotax 912 ULS - Fretted CrankCase

    by » 8 years ago


    Hi All,

    Interesting enough that today I had a fretted engine case come into my shop. It is only 73 engine numbers from the one reported above a 2005 912ULS and has 944 hrs on it. It has all the symptoms and I'm sure it is the problem after doing some test. Unless Rotax helps with parts cost this is a $12K to $14K fix by the time it's all back on the plane and labor and shipping are figured in.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

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