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fuel system problem????

Discussion in 'Mechanic and Repair' started by Fyduska, Aug 12, 2010.

  1. Fyduska

    Fyduska LawnSite Member
    Messages: 9

    I have a Hustler Super Z with Kohler Pro 30hp. The engine model is CV750S.

    Turning the key to the on position typically gives an audible sound of the fuel pump doing its thing. I can no longer hear the pump working??? The mower still starts and runs but stalls shortly after as if it is not getting enough fuel.

    I am a novice at best with small engines. Would rather fix this issue myself (got to learn sometime). Any advice on where to start?

    The fuel filter has not been replaced and is due so I will start there. Could this be just a clog or dirty filter? Does it sound like the pump is bad also?

  2. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,248

    I may be wrong but I believe the unit is equipped with a diagphram fuel pump rather than an electric fuel pump. The click you're used to hearing is the fuel solenoid. If you're not hearing it then either you don't have power to the solenoid, have a bad solenoid ground or the fuel solenoid is stuck in an open position. The latter is not likely possible as the engine should continue to run with the solenoid in the open position if the fuel pump is working.

    If the engine is equipped with a diagphram fuel pump, disconnect the fuel line from the fuel pump to the carb(at the carb) and with a container to collect the fuel, crank the engine to determine if you're getting a good fuel flow from the fuel pump. You may also want to check the fuel filter if you don't have good fuel flow.
  3. Fyduska

    Fyduska LawnSite Member
    Messages: 9

    Disconnected line and appears the fuel pump and the filter are running fine.

    Okay I may have been way off here but I just discovered that with a cold engine it cranks fine but when I engage the hydraulics to move forward it cuts off. The 12 volt fan above the engine that appears to cool the hydraulics is not coming on. Is it possible this is burnt out and causing this problem.

    When turning the key in the on position what fan would I typically hear running? I know longer hear it and wonder if this cooling fan for the hydraulics has gone bad.
  4. Ruben Rocha

    Ruben Rocha LawnSite Senior Member
    Messages: 577

    I will assume this unit is similar to a Hustler super mini z.
    The fan circulates air over the oil cooler for the hydraulics.
    So it would only be a issue on long running times.
    But, It could be a indication that you may have some other electrical problems.
    You need to start with checking if you have 12 volts dc to the fan with the key switch in the on position.
    You might have some bad connections that may also impact the fuel solenoid.
    Also as soon as you take the handles out of park it could be the seat switch is not working correctly.
    As soon as you move the handles to the neutral position the brake switches change state. So the seat switch is looking for presence to keep the engine running.
    Last edited: Aug 13, 2010
  5. Fyduska

    Fyduska LawnSite Member
    Messages: 9

    Thanks for the help.

    All fixed!!!

    The cooling fan over the heat exchanger for the hydraulics was not working.... fixed bad relay.

    The seat switch had loose connection... fixed.

    Only $7.50 for new relay and the satisfaction of not waiting weeks for the dealer to fix and charge my crazy amount.

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