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Thread: External Fuel Pump

  1. #1
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    Default External Fuel Pump

    Hello

    I am not allowed to change the jets on my carbie. The jet restricts the amount of fuel to add to the air to make it go bang. I simplify this because what would happen if I pump fuel into the engine prior to the actual fuel connector.
    Would more fuel simply by pressure alone pass the jet??

    Thoughts anyone.

    Brad

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    If you use an electric fuel pump you need to regulate the pressure so it does not go past the needle and seat. That will just flood the motor. Why not jet the motor. Jets are not terribly expensive! BUT if you dont know what you are doing it WILL go BANG! I have however used an aeromotive fuel pump controller on an OMC drag motor with carbs. Picked up over 200 rpm at the big end of the track.

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    Sam Cullis Mark75H's Avatar
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    Enrichening will only help if the motor is running lean.

    If you can get the motor to run lean, you may be able to enrichen the mixture a little by raising the float level ... increasing the fuel pressure will not help because the carb does not work by fuel pressure ... it works by jet size and float level
    Since 1925, about 150 different racing outboards have been made.


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    Sam Cullis Mark75H's Avatar
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    On the other hand ... if your motor is running richer than it needs, you may gain a small amount of power by leaning out the mixture.

    If changing jets is not legal ... you can lower the float level a little to lean the motor off ... if you dare
    Since 1925, about 150 different racing outboards have been made.


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    Or if changing jets is illegal, you can always resize your existing jets. I'm sure they could have been damaged somehow and you were simply repairing them. Stupid rules are excellent ones to work around!

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    Team Member zul8tr's Avatar
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    Default jet mods

    Quote Originally Posted by hydroplay View Post
    Or if changing jets is illegal, you can always resize your existing jets. I'm sure they could have been damaged somehow and you were simply repairing them. Stupid rules are excellent ones to work around!
    Ha that sounds like Smokie Yunick interpertation of NASCAR in the early days

    Here's the way it was

    http://sports.espn.go.com/espnmag/story?id=4046695

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