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  1. #1

    lean runaway after carb maintenance on 787

    Hi All,

    Recently got the 96 Challenger out for it's first start up after a couple of months to get ready for Summer (Australia). Did the normal prep.
    Boat was stuck on full throttle, diagnosed the issue as a seized throttle shaft.
    I'm since removed the carb, fixed the issue and reinstalled the carb, without making any adjustments.

    Started it up for the first time the other day since putting it back together.
    Just on the trailer on a hose.
    Began to rev pretty high with throttle at idle position (5500rpm), thought it might just be from the dry carbs.
    Killed the engine.

    Decided while I'm at it I'll clean the Rave's, so did that also.

    Next day, started it up again; on the trailer on a hose.
    Didn't seem to rev as high, but still 4800rpm and sat there for about 2 mins before I killed it again. Stopped fine with stop button.

    So a couple of questions.
    Considering the Rev's seem to be dropping (from 5500rpm to 4800rpm between runs), is it merely a case of running it out on the water under load to allow the carbs to get a bit more fuel in to stop it running lean? Or is there anyway to prime them? Or is this unlikely to be the problem?

    When I cleaned the Rave valves I was unsure if I should grease up the gaskets. Could there be an air leak there?

    Finally, I destroyed one of the carb base gaskets between the intake manifold and carb when removing. I was unable to find stock of this gasket at local seadoo dealers.
    Being fairly mechanically inclined but new to Seadoo's, I made a new gasket from rubber and cork gasket material. But didn't grease either side of it.
    Am I looking at the most likely cause?

    Appreciate anyone opinions

  2. #2
    take a squirt bottle of gas and lightly spray into intake, the rpm will drop, its basically the carb on the lean side, adding more low speed will drop it, but most likely will load up in water then

  3. #3
    kecheme's Avatar
    Join Date
    Jul 2011
    Phoenix Az

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