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Thread: Electric primer

  1. #1
    Senior Member ceslaw's Avatar
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    Default Electric primer

    Has anyone considered replacing the primer pump, with its two copper lines carrying 100 LL into the cockpit over the pilots feet, with an electric primer that keeps those fuel lines out of the cockpit and simplifies installation and operation?

    Aircraft Spruce sells a unit. Van's also sells the same one as a complete kit.

    I am not a fan of running oil and fuel lines into the cockpit for measuring fuel or oil pressure on the cars I have built for safety reasons. I was not aware of this option for the primer until an A and P mentioned it.

    Replacing the existing primer with a momentary on toggle switch and getting rid of the copper tubing would be an easy project. The primer would be mounted by the gascolator with a short line. There would then be a single line going to the primer port.

    Copper tubing fatigues and can fail. Another reason to remove the tubing from the cabin.

    I am looking for any thoughts or experience anyone might have.

    Here are a couple of links.


    https://www.aircraftspruce.com/catal...lsolprimer.php


    https://shop.vansaircraft.com/cgi-bi...duct=eng-prime

  2. #2
    Senior Member Andy's Avatar
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    Default Re: Electric primer

    Quote Originally Posted by ceslaw View Post
    I am not a fan of running oil and fuel lines into the cockpit for measuring fuel or oil pressure on the cars I have built for safety reasons. I was not aware of this option for the primer until an A and P mentioned it.
    You are surrounded by plastic fuel lines in the cockpit of a Carbon Cub. Why are you concerned about the primer lines? Unlike an oil gauge line the primer lines are not pressurized (unless you are actually using the primer).

  3. #3
    Senior Member ceslaw's Avatar
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    Default Re: Electric primer

    Quote Originally Posted by Andy View Post
    You are surrounded by plastic fuel lines in the cockpit of a Carbon Cub. Why are you concerned about the primer lines? Unlike an oil gauge line the primer lines are not pressurized (unless you are actually using the primer).
    Point well taken. But I have a lot more faith in the plastic lines carrying fuel than I do the copper lines. I have seen copper fatigue and crack over time, hence my concern.

    Add to that the occasional maintenance that the mechanical primer pump requires. If the primer is not fully seated excess fuel can bleed into the intake making one cylinder way to rich. Potential for leaks with the primer pump. The electric primer eliminates those concerns with a simple toggle switch.

    Perhaps I am fretting about a matter that is a non issue 99.9% of the time. Sort of like an ELT GPS antenna that can't put out an effective signal. In fact I did not have any issues with the mechanical primer in the last Cub, so perhaps keeping it original with old technology is just fine.

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