9.5hp tumbling coughing

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  • July 23, 2020 at 4:21 pm #209593
    crosbyman
    Participant

      Canada Member

      a 9.5hp I am trying to get going after doing the electricals, carb etc…. like many more I have done..

      this one is strange… it tumbles, coughs at about 1 – 2 second intervals when running at lower rpms at higher rpms I guess it has no time to cough

      I tried adjusting the LS needle to no avail

      any clues on what could cause this

      thanks

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      July 23, 2020 at 7:38 pm #209642
      fleetwin
      Participant

        US Member

        Well, it is running lean if it is coughing/sneezing. You mention that adjusting the low speed needle has no effect. Is the carb sync correct? Perhaps the carb butterfly is stuck open at lower speeds…This engine has some very strange linkage connecting the carb to the mag plate, it is easy to mess up…
        Have you had this engine running before, or is it new to you?

        July 23, 2020 at 7:56 pm #209645
        crosbyman
        Participant

          Canada Member

          ok i’ll check the linkages for proper butterfly closing at low rpm …..

          this is a new to me motor I picked it up for 50-60$ last year or… two ago I am just getting around to reducing the collection in the garage 🙂

          9.5-cam-adjustments

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          • This reply was modified 4 years, 11 months ago by Mumbles.
          July 24, 2020 at 11:15 am #209696
          GLEN DEUTSCH
          Participant

            Crosbyman,
            From the looks of your picture, this looks like a 9r69. I have the same motor. It will drive you nuts. Look it up on LeRoy ‘s ramblings. The carb needs to be spotless. If you remove the low speed welch plug, you will find a plastic plug. This plug is shaped to direct fuel flow. It is not a part of the carb kit. I have found no references of this anywhere except LeRoy. Marineengine has a replacement for a few bucks. The plug is hard to remove. Be careful not to damage the metal. If you have a spare carb to practice on, that would be helpfull. I have cleaned the carb countless times. I will be lake testing it again today. If it is still coughing at idle, I am going to replace that plug.Good luck.

            Glen

            July 24, 2020 at 11:47 am #209698
            crosbyman
            Participant

              Canada Member

              ok thanks I am familiar with the plug (plastic) picture in not my motor just a copy paste doc. I have fixed up a few 9.5 but this one was touchy

              thanks for comments

              Joining AOMCI has priviledges 🙂

              July 24, 2020 at 6:39 pm #209739
              outbdnut2
              Participant

                US Member

                Does it cough just at one slower throttle setting and run Ok at a slow idle? All motors have a throttle setting a bit above idle where they will not run smooth because it is transitioning from low speed carb jet to high speed just and is in a never-land in between.
                Dave

                • This reply was modified 4 years, 11 months ago by outbdnut2.
                July 29, 2020 at 3:50 pm #210306
                crosbyman
                Participant

                  Canada Member

                  update July 29…Success 🙂

                  first thanks everyone for all your comments Fleetwin’s clued me in to the basic problem 🙂 … sorry problems

                  Rechecked the throttle plate and it was not shut in the START position as describded in the manual and pic. above 🙁

                  I adjusted that section (cam follower) only to find out the tiller throttle START position was all screwed up because the tiller/throtlle gears did not mesh properly.

                  After adjusting everything one shot of choke and a pull or two did it…. started right up ok and no more tumbling on the low rpm’s

                  and I sold it the next day 🙂

                  Joining AOMCI has priviledges 🙂

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