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1979 75HP fuel issue

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  • 1979 75HP fuel issue

    I pump up the fuel line until it stops and the engine cranks fine. It seems to run until the gas in the bowls is used up and then tries to die. If I push the chokes in for about a half second (no longer) it runs good again for about 10 seconds. I can even throw it in gear and get a throttle. It acts like it is running out of gas unless I push the choke every 10 seconds or so. All the gas lines look good. I suspect the fuel pump.
    I also don't completely understand the plastic cover over the carb intakes. It has a gasket that looks like somebody was trying to add permatex to seal. What is the purpose of the cover and also the gasket?
    I really would appreciate some help with this. I bought this boat as a junker and gradually it is coming to life. WHEN IT IS RUNNING IT SOUNDS PRETTY GOOD.

  • #2
    The purpose of the carburetor faceplate cover and gasket is two fold. One is to keep anything from flying into the carburetor throats and from there into the intake manifold (unlikely but it has happened). The other is to keep the fuel mixture from dripping from the carburetors into/on the hood pan (messy).

    What drips in that area when it's sealed properly will travel into that short line you see attached to the faceplate a$$embly and into the bottom main bearing area to be recycled to the cylinders via other passageways.

    Your problem appears to be a failed fuel pump.

    Do this..... Pump the fuel line fuel bulb while the engine is running, acting as a manual fuel pump. If the engine continues to run as long as that bulb is pumped, then obviously either the fuel pump is faulty OR the pressure line leading to the crankcase is broken or disconnected, however IF that pressure hose is broken or disconnected, there will be quite a loud noise (explosion) coming from it while the engine is running.

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    • #3
      I got in a fuel pump today and it definitely repaired the problem. Cranked right up. Purrs like a kitten. I'm having a cooling issue now but I will probably get more answers if I begin another thread.
      Thanks for all of the help. It's nice to have some agreement on your suspicions before you buy parts.

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