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Carb issues

in General Tech Discussion 10 years ago

  • Re: Carb issues

    by » 10 years ago

    Hi Jerry,

    "After overhauling the carbs, I couldn't get any power out of the engine until I moved them down to the 3rd notch."

    Most likely because it was too lean.

    Do these carbs sync up at idle and at least 3500 rpm?

    If you are using the hot air inside the cowl or the air filters are mounted directly to the carbs then it is almost like running carb heat all the time. If this is true with hot air going into the carbs then you need to look and make sure the rebuild went as planned. There is no cold air into the carbs. This also richens the mixture some. Engines do run better when used with cool dry air. You may want to go back into the carbs and make sure everything is installed correctly. If the float level is too low then the engine may starve for fuel (similar to running in the second notch), the butter fly valve should have the punch mark on the top outside of the brass plate, the diaphragms may be off and not aligned with the notches or in the notch on the top of the piston (slide). Make sure the diffuse in the main jet is turned the correct way.

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

      
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  • Re: Carb issues

    by » 10 years ago

    Thanks Roger, I'll check into those things and let you know what I find.
      
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  • Re: Carb issues

    by » 9 years ago

    I believe that I found the problem with my left carburetor. I have some advise for anyone who works on a Bing 64 carburetor. The alumanum piston has a steel tube thru it that holds the needle and retainer screw. Be careful not to overtighten the retainer screw! If you do, the tube can turn and push down in the piston which will lower the needle position. I had to use a couple of sockets and a vise to press the tube back into the correct position in the piston. I compared the position to the piston on the other carburetor to make sure it was correct.
    I have not run the engine yet, but I'm sure that was my major problem.
      
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  • Re: Carb issues

    by » 9 years ago

    I have seen a few of these come loose. Fairly rare, but it can happen. It can be Loctited back in place.

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

      
    Report
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