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Increased RPM at take off speed or slippage?

in General Tech Discussion 9 years ago

  • Re: Increased RPM at take off speed or slippage?

    by » 9 years ago

    It is the overload clutch.
    Whoever did the work do they have the correct tools for this job? what was the break-away value? was it done with break-away or slipping values?
    There is a good reason why this work is limited to approved shops....
      
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  • Re: Increased RPM at take off speed or slippage?

    by » 9 years ago

    The first time done at CPS in corona Second time by Jan at Far-West Aviation. Everything was said to be within specs. Replaced Belle ville washers. In regards to the RPM It sounds like it would be more than 1000 rpm increase so I think it would have been noticable if it was but havnt seen any increase. Were going to do a ground test to see if we can get it to give by just increasing throttle while not in motion. But doing it under the 145 mark and see if it happens. Are there any videos out there of a slipper clutch giving?
      
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  • Re: Increased RPM at take off speed or slippage?

    by » 9 years ago

    Nope, no videos for the overload clutch overhaul/repair.
    Has moly or any friction modifier oil ever been used? That would explain why the clutch is slipping.
    I would replace the clutch, if the moly is embedded in the sintered bronze or steel discs I doubt any amount of cleaning will get it out.
    Lots of used clutches available with the 912iS sport kit coming with a new clutch, you just need to insert your hub to make it compatible with the 912ULS. Don't use the 912iS hub.
      
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  • Re: Increased RPM at take off speed or slippage?

    by » 9 years ago

    So we have been watching the video over and over again. If you watch closely you can see that the prop slows down when it increases rpm. We agree that it is the clutch. Are any of you on here interested in fixing this?

    By the way thank you all for the replies!
      
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  • Re: Increased RPM at take off speed or slippage?

    by » 9 years ago

    Hi All,

    The same thing happened to us several years ago and we just replaced the gearbox as we had a spare one lying around and problem was solved. Roger might be right! May be the your gearbox was not done right or something might have gone wrong after assembley!
    Anyways, I just wanted to share this with you that we had a similar problem and was resolved when we changed the box.. We never bothered to open it up and check what was wrong inside.

    Regards,

    Andre' - Middle East / UAE
      
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