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Thread: 912 exhaust connections

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  1. #1
    Senior Member
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    Default Re: 912 exhaust connections

    I think they are far more likely to break on a pusher configuration where the little devils have the most chance of doing damage, especially if you didn't safety wire them. I've never had one break on me either, but have removed some that were quite worn, and if left to themselves would have eventually called it quits. I think the silicone will help keep them from vibrating and therefor have less wear. JImChuk

  2. #2
    Senior Member jiott's Avatar
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    Default Re: 912 exhaust connections

    I have replaced several that were on the verge of breaking; and I have had the silicone on from day 1, now 660 hours.
    Jim Ott
    Portland, OR
    Kitfox SS7 flying
    Rotax 912ULS

  3. #3
    Senior Member cap01's Avatar
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    Default Re: 912 exhaust connections

    i just had to remove the exhaust system to repair some cracks and a couple of the springs were worn so bad that there was so little metal left i could hardly see it, i don't know why they hadn't let go. they had almost 1100 hrs on them and had the hi temp silicone on them. when i installed the pipes i used silver anti seize
    chuck
    kitfox IV 1050
    912ul warpdrive
    flying B , yelm, wa

  4. #4
    Senior Member fastfred's Avatar
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    Default Re: 912 exhaust connections

    I would probably plan on replacing the springs more often but still I have not heard of one breaking.1100 hours is pretty good on a $3 spring

  5. #5
    Russell320's Avatar
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    Default Re: 912 exhaust connections

    Well....here it is...fresh off the airplane. What a pain that was. The cracks are from the two rear headers. Unfortunately, I don’t think I can save the muffler......a new one will be $795 from Kitfox and is custom made for your headers. It takes about 3 weeks. My guess is the cracks are from the slip joints not slipping. The muffler is from the early 90’s, so I’m not willing to fix it and then have it crack again from age. But......I may change my mind.

    Mouse milk, mapp gas and a week of soaking finally did the trick. Did I mention it was a pain?
    Russ
    Model IV Speedster
    912UL IVO IFA
    RV6A
    Needle, Ball and Airspeed
    Maybe a little GPS

  6. #6
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    Default Re: 912 exhaust connections

    Weld it up and keep the joints freed up. Heat the collars up red hot and woller them open a little. That will help in keeping them able to slip freely.

  7. #7
    Super Moderator Av8r3400's Avatar
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    Default Re: 912 exhaust connections

    Unfortunately that muffler has become so work hardened and fatigued, just welding the cracks will fail again very quickly. I added reinforcing plates on my last muffler over the cracks. That helped but also re-oriented the sleeves just enough that getting the pipes to line up was almost impossible. Then the stinger and blast tube failed rendering the muffler scrap.

    The permanent fix would be to cut off the sleeves and replace them with ball joints.
    Av8r3400
    Kitfox Model IV
    The Mangy Fox
    912UL 105hp Zipper
    YouTube Videos

  8. #8
    Russell320's Avatar
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    Default Re: 912 exhaust connections

    Yep....tried all that too. Using Pete’s idea with a 3/8th nut,bolt and socket. Using mapp torch hasn’t worked, so acetylene is next. Thanks for your suggestions....keep em’ coming!

    BTW...don’t expand too far with this setup....you’ll bend the tab into the header.
    Attached Images Attached Images
    Russ
    Model IV Speedster
    912UL IVO IFA
    RV6A
    Needle, Ball and Airspeed
    Maybe a little GPS

  9. #9
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    Default Re: 912 exhaust connections

    I can't imagine that the bolt as you show it between the spring tabs plus heat from a torch wouldn't work. Unless it somehow welded it's self together. (not likely) Show us pictures of your success! JImChuk

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