Suzuki 2hp 2stroke fuel system conversion

Discussion in 'Outboards' started by SpiritWolf15x, Oct 27, 2012.

  1. SpiritWolf15x
    Joined: Apr 2010
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    SpiritWolf15x Senior Member

    Hey everyone, I have a 2hp Suzuki that runs really well, the only problem is that the on board fuel tank is only good for about an hour and a half of motoring. I'm trying to get my 16' trimaran up to par for PIYA category 3 classification and one of the requirements is that I can motor for 6 hours if needed and refueling while underway is just dangerous.

    What I'm wondering is if anyone on here knows of an easy and inexpensive way to convert the motor to feed from an external tank.

    Thanks,

    Rob
     
  2. CDK
    Joined: Aug 2007
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    CDK retired engineer

    That engine probably has no fuel pump, so it needs gravity to get fuel.
    The cheapest solution is a fuel tank in a pedestal. As an alternative you could look for a very small carb with an integral pump, like those used in chainsaws.
     
  3. Frosty

    Frosty Previous Member

    They do not have a pump CDK is right they are gravity fed. You could fit and external tank of any size you want, anywhere on the boat as long as its higher than the carb.
     
  4. FAST FRED
    Joined: Oct 2002
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    FAST FRED Senior Member

    Find an old Evinrude tank from long ago. These have built in pumps that will pressurize the tank itself..

    Then install a pressure regulator before the carb to not flood the engine.

    A couple of 6 gallon tanks could be changed on the fly so your range would be extreme!!
     
  5. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You can gravity feed the existing tank from an outboard type tank that is installed higher than the motor. The setup has two hoses going from the feed tank to the one mounted on the motor. One hose goes from the feed on the higher tank to the one in the outboard. The other goes to the vent. As the fuel gets lower and the end of the vent hose is exposed, air enters the higher tank and fuel flows into the outboard's tank.
     
  6. SpiritWolf15x
    Joined: Apr 2010
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    Location: Vancouver, Canada

    SpiritWolf15x Senior Member

    So I can probably get away with taking the built on tank off and rerouting the petcock line up to a fuel fitting. Right?
     
  7. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    That would work fine. Make sure the tank is not too high or the fuel pressure may end up being too much and flood the carburetor.
     
  8. Frosty

    Frosty Previous Member

    A fuel tank mounted on a pedistal would not look attractive and would be a concern in a thunder storm. If you don't want to put it high up then put it low and fit an electric fuel pump. A small tick pump is cheap some are so small motorcycles use them.

    I don't agree that it will flood the carb . The tiny needle and seat will handle a higher pressure than a larger one and the pressure they develop is from priming a spring that can be as small as 3---4 psi.

    The Holley types is for 600 cfm carbs needing 100+ liters per hour consumption where as your will be 2.
     
  9. SpiritWolf15x
    Joined: Apr 2010
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    Location: Vancouver, Canada

    SpiritWolf15x Senior Member

    The motor is only going to sit less than a foot below the cockpit floor height where the tank is going to be located so I don't think it'll build up that much pressure.
     
  10. tunnels

    tunnels Previous Member

    My son used to use a white plastic tank so could see the petrol level inside and a hose directly to the motor and a one way valve ! the second short hose also withh a one way valve he would simply blow hard into the hose and pressure the 6 litre white plastic tank ! he could blow enought pressure to keep the motor going for ages and if it slowed he'd blow another couple of puffs and away he'd go again !!
    For a 10 year old kid i reckon it was pretty clever !!.:D
    I used to have to keep the 6 litre white mover fuel tank hidden out of sight . :p
     
  11. SpiritWolf15x
    Joined: Apr 2010
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    Location: Vancouver, Canada

    SpiritWolf15x Senior Member

    I'll post pictures of the project as soon as I start working on it, stay tuned folks.
     
  12. Liighthead
    Joined: Jul 2012
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    Liighthead Junior Member

    sounds good spiritwolf

    with tunnels idea, small hand pump? instead of blowing hahaha
    but yeah same idea :) even a bigger tank ( 15L or something haha ) simply pump when ur fuel gets low
     
  13. SpiritWolf15x
    Joined: Apr 2010
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    SpiritWolf15x Senior Member

    It is getting converted to gravity feed off a 20L outboard tank, as that is all I have on hand. (no simply going to Westmarine and buying a new one is NOT possible) At one or so liter per hour or so it should get me more than enough range.
     
  14. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    A garden sprayer with the hose fitted into the tank cap would allow in flight refueling. Might not trust the spreader valve so just fit a good valve in the line and pre-pressure the tank. A simple wire and cork float poking through the cap (like in many light aircraft) would be a good fuel gage.
     

  15. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    I had the same problem, and just installed a hand pump on a feed line between the tank and the motor. Then I took a small barb fitting and tapped it into the motors tank. This way I can run the motor with just the internal tank for day trips, but if I need the extra fuel I don't have to deal with trying to refill on the water (except by giving th episode a few throws).
     
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