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  1. #1

    1999 SLTH No Start after running all day

    So little back story. 1999 SLTH, rebuilt carbs with real mukini rebuilt kit, new fuel lines, plugs ECT.

    Ski had been great and always started just fine since I rebuilt the carbs 2 years ago. Last weekend after running fairly hard for about 25 minutes, it struggled to idle and died. I tried to restart, but no go. Cranks over no problem. Brought it back to shore and on the lift, check the plugs, and both have spark. So I'm thinking fuel. Grab some premix from the shed and drop a little in each carb and it fired right off. So, I drop the ski in the water, little more fuel in each carb and again, fired right off. I drove in a circle for a few minutes and blipped the throttle a bit and everything seemed to be fine.

    But by this time it was getting close to dinner time, so back on the lift and called it a night.

    Question, can these things vapor lock?! Kinda seemed like a similar situation.

    But any other ideas?

    Any help is great.

  2. #2
    Click avatar for tech links/info K447's Avatar
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    Not vapor lock, per se, but perhaps an air leak into the fuel system. The entire fuel system is under suction from fuel tank to fuel pump.

    An air leak at the water separator, or the fuel selector valve, even at the fuel sender, or even at a hose clamp, can allow air bubbles into the fuel feed hoses.

    Also check the health of the pulse hoses that power the fuel pumps. A loose or leaking pulse hose will diminish fuel flow.

    When it stopped running while on the water did you loosen/remove the fuel filler cap? Was there a huge air suction into the tank or a positive pressure flow out of the tank?

    If the fuel tank venting check valve is sticking closed that can create a vacuum effect inside the fuel tank, starving the fuel pump for fuel flow.

  3. #3
    Quote Originally Posted by K447 View Post
    Not vapor lock, per se, but perhaps an air leak into the fuel system. The entire fuel system is under suction from fuel tank to fuel pump.

    An air leak at the water separator, or the fuel selector valve, even at the fuel sender, or even at a hose clamp, can allow air bubbles into the fuel feed hoses.

    Also check the health of the pulse hoses that power the fuel pumps. A loose or leaking pulse hose will diminish fuel flow.

    When it stopped running while on the water did you loosen/remove the fuel filler cap? Was there a huge air suction into the tank or a positive pressure flow out of the tank?

    If the fuel tank venting check valve is sticking closed that can create a vacuum effect inside the fuel tank, starving the fuel pump for fuel flow.
    Great info and thanks.

    Unfortunately, I did not check much of the fuel system after the issue. Just checked the plugs knowing spark can be an issue on these machines. But, I believe I changed the pulse line when doing the fuel lines, if not I'll change it regardless.

    I'll do a little check over what you mentioned and see if I find anything fishy.


  4. #4
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    Another thing to check is to make sure none of the gas lines have to tight of a curve/turn to them, especially near the water separator area where it's a tight space. The negative pressure in the line can collapse a gas line pretty easy in a curved/turn area.

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