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cylinder 1 and 2 are burning much too dark

in 912 / 914 Technical Questions 13 years ago

  • Re: cylinder 1 and 2 are burning much too dark

    by » 13 years ago

    Set your 912ULS idle up around 1750-1800 rpm and your engine will love you and the vibration and gearbox beatings will cease.

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

      
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  • Re: cylinder 1 and 2 are burning much too dark

    by » 13 years ago

    Gearboxes will try to beat themselves to death much below 1700 yet some a/c manufacturers ask that the engine be set up anywhere from 1450 to 1600 rpm's.Very confusing to those that don't know..
    Thank you said by: milo avram
      
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  • Re: cylinder 1 and 2 are burning much too dark

    by » 13 years ago

    This is where the Rotax manual falls a little short. It states 1400 min rpm, but does not explain the difference between the 912ULS and 91UL idle rpm and why the difference. Rotax separates the two engines in other parts of the manual, but falls short here. It is taught correctly in Rotax school and I would highly recommend that anyone that has a 912 engine go to at least one 2 day school and have a good basic understand of their engine and what the differences are between the 912UL and 912ULS. A 1500 idle rpm for the 912ULS is detrimental to the engine.
    The little things can make a difference in how your engine runs now and in the long haul.


    Rotax if you are reading these please put a a revision page to address the idle theology between the two engines so everyone that only has a manual will know the why's.

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

      
    Report

  • Re: cylinder 1 and 2 are burning much too dark

    by » 13 years ago

    I have seen the aftermath of low idle and bad carb sync since 1996.These two areas cannot be stressed enough...The 80 horse is alot more forgiving than the 100.Lower compression,smaller bore and different gear ratio helps too.I strongly urge operators as well as techs to go to the classes...Wealth of info!
      
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  • Re: cylinder 1 and 2 are burning much too dark

    by » 13 years ago

    please remember, operation idle is at ~ 2 500 rpm, when ever save and sensible,
      
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