Airhead sounds like a jiffy pop

Discussion in 'Airheads' started by squirrelscoundrel, May 17, 2010.

  1. squirrelscoundrel

    squirrelscoundrel beginner metal jockey

    Joined:
    Apr 20, 2009
    Oddometer:
    45
    Location:
    Fabulous Rhode Island
    My r75/6 sounds like a jiffy pop when it is warmed up and revved higher than 5,000 RPM or it is sitting in traffic and hot at lower RPM. There is a pop pop pop pop coming from the Left Cylinder or the Left Carb (I think that it is the carb) There was originally a leak between the L tube and the carb which I fixed. Before I fixed it, Every time it would pop, there would be air coming out of the leak in the coupling. The bike rode fine for about 50 miles after the fix and then began to pop again on the highway. The seal (duct tape) is still good, but it is still popping and is barely capable of highway speeds because when she starts popping, the power declines considerably. Does anyone know what coulc be causing this? Too much gas? not enough gas? Too much air? not enough air? How can I fix this? Thanks a lot for your Help. As always, it is appreciated.

    Doug
    #1
  2. caponerd

    caponerd Kickstart Enthusiast

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    Maybe a badly leaking intake valve?

    Run a compression test. If it's low, squirt some oil in the sparkplug hole and try again. If it's still low, you got a bad valve.
    #2
  3. bmwblake

    bmwblake upside down parker

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    make sure the metal piece that screws into the head where the rubber between the carb and the head meet is tight. you'll have to remove the carb and the intake rubber to access it.

    number 4 in the image below.

    [​IMG]
    #3
  4. squirrelscoundrel

    squirrelscoundrel beginner metal jockey

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    Thanks for the advice. I appreciate it.
    #4
  5. evildonald

    evildonald Shrubber

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    You are likely using the wrong brand of duct tape!:rofl
    But seriously, it sounds like an intake valve too tight to me.


    MY $.02
    #5
  6. Cigars&Scotch

    Cigars&Scotch My eyes are up here

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    On BMW's, You must use metric duct tape. That is the only kind that works.
    :lol3:lol3:lol3




    Cover the ends of the exhaust while running and check for leaks in the exhaust system.
    #6