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  1. #1

    no gas tank pressure

    Does anyone have any suggestions as to why there is no pressure in my gas tank when i unscrew the cap? I just replaced the gascap gasket but that still didnt seem to fix the problem. It seems to make the ski very hard to start when its warmed up and it bogs a low speeds.


  2. #2

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    It could be leaking at the rubber seal on top of the gas gauge (where the fuel supply and return lines stick out of the tank). Use a compressor to pressure the tank to about 10 lbs by going into the filling hose and listen for air escaping. Spray with windex and check for bubbles. It can only leak there or at the little white pressure relief valve. That line sticks out of the same gauge and goes up toward your handlebars.

  3. #3
    mudslanger's Avatar
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    Check the pressure relief valve it may need cleaning or replaced. air will go in one way and restricted the other way

  4. #4
    Thanks, Ill try and pull the relief valve, hopefully its an easy fix

  5. #5
    PolarisNut's Avatar
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    Quote Originally Posted by bsmith45 View Post
    Does anyone have any suggestions as to why there is no pressure in my gas tank when i unscrew the cap? I just replaced the gascap gasket but that still didnt seem to fix the problem. It seems to make the ski very hard to start when its warmed up and it bogs a low speeds.
    The "fuel tank pressure" isn't your issue. You need to figure out why its leaking, but that isn't the cause of your hard starting and bogging. You have something else wrong with your fuel system.

  6. #6
    GoFastGuru's Avatar
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    you are are crazy sombody clear this up this is very irratatating it is your proublem no question, . not starting any slams let the guy fix his ski without all this replace the check valve

  7. #7
    mudslanger's Avatar
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    Quote Originally Posted by PolarisNut View Post
    The "fuel tank pressure" isn't your issue. You need to figure out why its leaking, but that isn't the cause of your hard starting and bogging. You have something else wrong with your fuel system.
    When you firs crank your ski you usually do not have tank pressure after sitting for a wile not in the sun. THAT'S WHY YOU HAVE TO USE A PRIMER OR A CHOKE. after the ski has been run it builds tank pressure when you turn it off the pressure on the tank keeps fuel pressure against the needle seat in the carbs resulting in easier starting and keeps the ski from running lean at high engine RPM.

    As far as the bogging at low speeds if its ideling for a long time you have to blow out the water box.

  8. #8
    GoFastGuru's Avatar
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    brad ask frank about his ski stumbling out the hole .no tank pressure bad tank seal and check valve replaced them and it jumps out of the hole like a cobra race him

  9. #9

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    Quote Originally Posted by mudslanger View Post
    When you firs crank your ski you usually do not have tank pressure after sitting for a wile not in the sun. THAT'S WHY YOU HAVE TO USE A PRIMER OR A CHOKE. after the ski has been run it builds tank pressure when you turn it off the pressure on the tank keeps fuel pressure against the needle seat in the carbs resulting in easier starting and keeps the ski from running lean at high engine RPM.

    As far as the bogging at low speeds if its ideling for a long time you have to blow out the water box.


    +1

  10. #10
    PolarisNut's Avatar
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    Quote Originally Posted by mudslanger View Post
    When you firs crank your ski you usually do not have tank pressure after sitting for a wile not in the sun. THAT'S WHY YOU HAVE TO USE A PRIMER OR A CHOKE. after the ski has been run it builds tank pressure when you turn it off the pressure on the tank keeps fuel pressure against the needle seat in the carbs resulting in easier starting and keeps the ski from running lean at high engine RPM.
    Are you serious? That is honestly laughable.

    A cold engine requires a primer or choke because the low head/cylinder temps don't allow the fuel to properly vaporize during combustion, so extra fuel has to be supplied. It has nothing to do with fuel system pressure!!! All gasoline engines function this way...carbureted or fuel injected.

    The fuel pumps supply fuel to the carbs with pressure...that is what they are there for. The fuel tank holds pressure for safety and emissions reasons...That is THE only reason. Sure, the pressure created in the tank technically increases fuel system pressure, but if your pumps are working correctly, it is a moot point.

    Now if you are creating a vacuum in the tank, then it will create a problem. It will start restricting the pumps. Once the vacuum gets strong enough, the pumps won't be able to pull fuel from the tank. This is where I have seen issues with the check valve getting stuck.

    BTW, I blazed past Frank last weekend, with my fuel tank cap flapping in the 80mph breeze.

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