Kohler efi, fuel drains out air filter when changing blades?

Discussion in 'Mechanic and Repair' started by Dawson, Jul 3, 2012.

  1. Dawson

    Dawson LawnSite Senior Member
    Messages: 913

    As the title says, I am getting a good amount of fuel flowing out of the air filter when I have the mower tipped up changing blades. It doesn't do this everytime but it has happened twice now out of the last four blades changes and I had to crank the engine for 30 seconds or so to get it running again this last time.

    Any idea what could be causing this intermittently?....it's a 29hp kohler efi that came on my exmark I bought 8 months ago.

    Thanks for any info:)
  2. Snyder's Lawn Inc

    Snyder's Lawn Inc LawnSite Platinum Member
    Messages: 4,530

    you sure its coming from the air filter
    you have spec number model you better post that

    THEGOLDPRO LawnSite Fanatic
    Messages: 5,222

    try turning the fuel supply off on the fuel line before changing blades.
  4. Dawson

    Dawson LawnSite Senior Member
    Messages: 913

    positive....gas was running out of the water drain slots on the underside of the filter "box" and both air filters were soaked with gas on the bottom side closest to the air intake so it was definitely flowing out of the air intake and through the filters.

    engine model is ECV749 with a manufacture date of 2-7-2011.
  5. Dawson

    Dawson LawnSite Senior Member
    Messages: 913

    I know I could do that but why is it happening? I've had it up changing blades numerous times in the last 8 months and this problem has just started happening in the last 3 weeks.
    Something in the fuel system is staying open that should be closed when the engine is shutoff I'm guessing.
  6. 65t

    65t LawnSite Member
    Messages: 65

    How far are you tipping it? The fuel pump module on the side of the engine (oil filter side of the engine with a yellow electrical conector on it) has a float inside, like a carb. It you raise the unit too high--fuel tanks too far above the module, the module will overfill and you get liquid fuel out of the vapor vent on top of the module. The vapor vent is connected to the air filter side of the throttle body. So gas will flow from the tanks into the module and out of the vapor vent into the throttle body and finally the air cleaner. Shut off the fuel, or don't lift it as high is the simple answer.
  7. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,337

    Good info 65t...sounds like you've seen this happen before...
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  8. Dawson

    Dawson LawnSite Senior Member
    Messages: 913

    I see....., It's at approx. a 45 degree angle while I change the blades, do you think that is enough to cause that to happen?

    I guess the main reason I'm posting is to find out if this was something I need to get it in the shop right away to have checked out or likely a minor issue that can wait till the season slows down to get checked out...even one day in the shop during the work week is a huge hassle for me as far as getting all my work done for the week and the local shops have a hard time getting anything done in that timely a manner.
  9. 65t

    65t LawnSite Member
    Messages: 65

    I don't think you have anything to worry about as long as it runs good when you're cutting. There is nothing in the FPM (fuel pump module) that is servicable, and they are not cheap to buy, unless you can get it covered under warrenty.
  10. ricky86

    ricky86 LawnSite Silver Member
    Messages: 2,139

    If it has a vapor recovery system, it could be getting pushed up through there.

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