Every once in a while I get a terrible noise when starting. I thought at first it was the gearbox. It sounded as if the dog ears were going past each other. I have overhauled the gearbox with new springs.  Thoroughly cleaned the clutch etc. The tension test is about 240 in # which is on the low side, but once in a while, It is still doing the noise. I did notice that the dog ears do look worn and should be replaced, but could that be causing this problem? Could it be that the clutch slipping?

I don't think it is the sprag clutch as it doesn't kick back when It starts.

Any suggestions?


  • Re: Terible noise when starting

    by » 12 months ago


    This may still be the gearbox. Send it in to a Rotax Service center. One the 240 in/lbs is way low. Normal tends to be between 440 - 490 in/lbs. Most likely not the slipper clutch, but there are other things at play here and they all need to be examined by a trained eye. The more you run the gearbox in bad shape the more expensive it is going to be to fix. Do it sooner than later.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

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