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Total loss of power

in 912 / 914 Technical Questions 12 years ago

  • Re: Total loss of power

    by » 12 years ago

    Hi Roger

    Just a bit off topic, and just for my own information, what happened when you said you lost a lifter. What failed and what damage was done, if any. I would like to know out of interest. Was there any warning and how many hours (ish) were on the engine.

    Cheers Roger

    Mark
      
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  • Re: Total loss of power

    by » 12 years ago

    Hi Mark,

    It only happens to 1-2 engines a year. The hardness coating on the lifter that rides against the camshaft breaks down. The lifter surface is very smooth and looks like a mirror surface, but a hard coating. The the metal surface of the lifter starts to grind down instead of just riding on the cam surface. It happens fast. The engine will burble for just a split second. Then it happens again and again in close succession and the burbles get closer together until the whole engine is running rough and shaking. You'll have lost one cylinder and running on 3 which gives you very little power. Nothing makes it better. The lifter keeps getting ground down just like it was against a grinding wheel so long as the engine runs. you can not shut it down fast enough nor would you even know what was going on until it was too late. That meant that my #1 exhaust lifter, rod and valve weren't working any more. On landing you will find the plugs to that cyl. wet and black. At this point the engine is destroyed. The grindings are in every orifice, journal and bearing in the engine. The mag plug will look as it has a beard, the metal grindings will be in the oil filter and in the oil tank. There won't be any chunks, just metal dust. These grindings are quite fine. There is no fixing this engine. It's now a teaching engine.

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

      
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  • Re: Total loss of power

    by » 12 years ago

    Thanks for that Roger, would it down to high hours or just poor hardening that has slipped through the net.

    How many hours had your engine on it before it happened.

    Cheers Mark
      
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  • Re: Total loss of power

    by » 12 years ago

    That engine had 833 TTSN hrs.
    It was just a poor hardening that slipped through the system.

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

      
    Report

  • Re: Total loss of power

    by » 12 years ago

    Hi all,

    I finally found the error. Could not believe it until I read the Maintenance Manual Heavy. Section 73 Page 32.
    The Float Needle has excessive wear.
    I fixed it temporarily by bending the float suspension brackets just to see if it was the cause. It worked. Now I will replace the parts on both sides BEFORE THE NEXT FLIGHT!

    Thanks again for all your helpful answers!

    Hans
      
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