1977 Evinrude 9.9 10724A carb leak

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  • April 28, 2017 at 5:59 am #6868
    PugetSoundBoater
    Participant

      Working on a friends motor. He said it ran last summer for a few minutes on the boat and would quit. So i thought fuel delivery issues. The motor has sat all winter. I checked the cleaned out tank ,fuel tank lines and delivery to the fuel pump with fresh gas ,all ok. I squeezed the primer bulb till it got hard, then noticed the bulb slowly collapse. Found a fuel leak in the horizontal carb vent hole at top left looking at the front of the carb. I suspect this is due to the inlet needle stuck closed and diverting gas out this vent ,and generally dirty,gummed up carb? With the motor sitting 1/2 hour while we had lunch, the carb evidently cleared and with a lot of attempts and a couple small shots of starting fluid(i know not a good practice) got it running ok in a barrel for over a half hour.It would restart on the first pull,no choke. I reset the low speed needle to about 2-2 1/4 turns out from closed .
      Checked spark on a open air gap homemade tester , got a 7/16th jump ,but it didn’t look like a blue spark,more orange. Coils are fairly rusty. Plugs are ok and the correct Champions.
      Seems to run cold as compared to my 9.9, i assume a stuck open t stat. Pumps water ok.
      Forgot my compression gauge today, will check the compression and fuel pump pressure before going further.
      I recommended a carb kit and the usual neglected /"deferred" maintenance, complete water pump, t-stat and gear oil. This salt water motor has had zero maintenance in the 5 years he has had it.
      Never seen a 9.9/15 carb leak at the vent hole before.
      Any comments or suggestions would be appreciated,have i missed anything to test?
      Thanks ,Jim PSB

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

      April 28, 2017 at 12:57 pm #56762
      fleetwin
      Participant

        US Member

        I’m not quite sure just what vertical passage it is that fuel was spilling from, but am guessing it was the bowl vent. I’m guessing the inlet needle was a bit stuck/gummed up causing the carb to flood. Once you got it running, and fresh fuel pushing through, the issue rectified itself. But, I’m sure you are correct, the carb is probably a bit gummy, which will eventually lead to more issues.
        Nonetheless, I would not argue with success, doesn’t sound like your friend is too interested in routine maintenance (paying for it). Don’t worry too much about those rusted coils, a fairly normal condition on salt water engines. And, just because the coils look like crap, does not mean they are broken/need to be replaced. Some of these coils even show cracks but do not leak. I’m sure your friend will be back if ignition problems develop.
        Your friend is making a mistake if he doesn’t invest in maintenance on this engine, these engines are tough to replace these days.
        One final note, this engine is not subject to the imfamous upper water tube issues. These early models had a different grommet design which was not problematic. But, be very careful if you decide to get involved with servicing this salty dog, I don’t want you left holding the bag with broken bolts resulting from a lack of proper maintenance.

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