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  1. #1

    Default Tohatsu 18 loosing fuel prime ???

    I have a Tohatsu M18E2 2-stroke. It runs wonderful, but when I shut it off, about 1/2 hour later, the fuel will have drained out (somewhere/somehow!?), so I always need to pump fuel with the hand pump, and sometimes it is a real pain to start the engine. It also runs rough sometimes after starting for a little while, like it's sucking air in the fuel line. This just started recently. Before that the engine started instantly with the slightest pull every time, and ran as smooth as silk.

    I replaced the fuel tank (with a new quicksilver tank), fuel line and hand primer pump, and yesterday I even removed the fuel line connector at the motor and connected the fuel line directly to the fuel filter. It still looses fuel after not running for a while.

    Thanks in advance for your help....

  2. #2
    Join Date
    Mar 2010
    Location
    Buffalo, NY, USA
    Posts
    2,080

    Default Re: Tohatsu 18 loosing fuel prime ???

    Is the new tank the EPA type, without a separate atmospheric vent?
    Is there any visible fuel under the carb (dripped out)?
    If not running, does the fuel system hold prime?
    Paul
    Buffalo NY USA

  3. #3

    Default Re: Tohatsu 18 loosing fuel prime ???

    The vent is on the fill cap.
    No sign of dripping fuel under the carb.
    No - that is my problem. Withing 20 minutes of shutting it off it has lost prime.

  4. #4
    Join Date
    Mar 2010
    Location
    Buffalo, NY, USA
    Posts
    2,080

    Default Re: Tohatsu 18 loosing fuel prime ???

    Then the issue is gravity allowing fuel back past the primer bulb to the tank, Especially if the tank is low and the check valves in the bulb poor, that could happen. If you test by raising the tank up above the height of the carb and the problem goes away, you have diagnosed a leaky bulb.
    Paul
    Buffalo NY USA

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