1985 Johnson 8hp running rough

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  • April 16, 2018 at 7:34 pm #74134
    fisherman6
    Participant

      US Member

      Unless you have a large fan blowing the exhaust away from the intake, the exhaust in the barrel can cause plenty of idling problems. Try the boat test and let us know how it goes.
      -Ben

      OldJohnnyRude on YouTube

      April 16, 2018 at 7:52 pm #74135
      davesko
      Participant

        Thanks Ben, Got my big run fan out and she runs well. Going to boat test soon.

        April 16, 2018 at 8:39 pm #74136
        crosbyman
        Participant

          Canada Member

          yep…. getting sick and sputtering sucking up exhaust…. or lack of oxygen ..

          I have a 9.5 turtle in the basement that I purchased ….. came with a 2 inch lobotomy close to the carb to let the air in 😯

          Joining AOMCI has priviledges 🙂

          April 17, 2018 at 1:48 am #74151
          james-davis
          Participant

            sounds like the hood is blocking something, air, or pinching line. has to be restricting something if it runs fine without it.

            April 17, 2018 at 4:32 am #74155
            PugetSoundBoater
            Participant

              There is a open vent baffle hole in the back of the hood handle or down in the lower cowl below the carb that is open to the outside that lets air in. Could that have become restricted? I know it sounds like a long shot, but as Don says "never say never". You never know what a previous owner has done. Many of us have seen some pretty odd "repairs" done for unknown reasons.

              "Some people want to know how a watch works, others just want to know what time it is"
              Robbie Robertson

              April 17, 2018 at 2:01 pm #74164
              fleetwin
              Participant

                US Member

                OK, are you saying the engine runs OK with the hood off, but messes up with the hood on? You have replaced the fuel pump and it acts the same way, correct?
                If indeed the engine runs poor with the hood on, it probably means one of two things…
                And exhaust leak under the hood…This should be fairly obvious, black soot/oily residue, noisier due to exhaust leak…
                Plugged up air inlets….I think the air inlets are under the hoods lift handle, thin little slots back under there. Perhaps there is some paper or tape plugging them up….
                And yes, you can not judge much running in the tank. Crazy water flow, and the tendency to breath its own exhaust just adds confusion to the issue…Try it out on the boat, try to make a video if the engine is still misbehaving…

                April 17, 2018 at 2:50 pm #74167
                davesko
                Participant

                  Hi Don, I changed the fuel pump and it seems fine even with the hood on. It was idling rough until I put my big fan on it. I’m going to boat test this weekend and know for sure. It’s always been a good runner till I loaned it out. Lol. I see no signs of exhaust leakage underhood so I think it should be good. Thank you

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