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header noise

Discussion in '40- & 55-Series Tech' started by surf40, Aug 2, 2005.

  1. surf40

    surf40

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    Just had my 772f rebuilt and am hearing a knock at high rpm or is it rumble from header? carb and intake are good and motor runs great. Only have 200 miles on rebuild hopefully I am overeacting and am not used to header sound. thanks for any input.
     
  2. ken_79-fj40

    ken_79-fj40

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    I would guess it depends on what you consider to be "high" as far as rpms are concerned. Most 2f's don't like to go past 4 grand. And my header doesn't make any knocking noises. But most headers allow you to hear the exhaust pulses a lot more clearly. But at high rpm you shouldn't really be able to hear that. I once had a knocking noise that appeared under load at higher rpms. It was my balancer about to fall off. Didn't realize it until I went to change the belt.
     
  3. surf40

    surf40

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    thanks for input ken, I think a rod is knocking and am going to drive a little bit longer, than back to shop for oil change, but it looks like motor will be out again. bummed about spending almost $4k on this rebuild, hopefully they'll take care of it. jeremy