I am testing fuel flow on a newly built Zenith CH750. I have 17GPH flow from the line at the carb. with the electric pump on and with the fuel flowing through the mechanical pump (engine not running). If I shut off the fuel pump and allow only gravity to feed fuel I get only 2.3GPH.(engine not running) This seems low. The wing tanks have only one gallon of fuel in each (one tank per wing) so the amount of "head pressure" is minimal.The bypass valve in the electric fuel pump is working correctly as I get good fuel flow after the electric pump with the pump not running.I am wondering if this is acceptable and normal?? Ideas,comments,suggestions appreciated.
  • Re: 912uls Fuel Flow

    by » 11 years ago

    Hi Richard,

    For what you describe it sounds about right. I have a high wing Flight Design CTSW. I can pull the lines off the fuel pump and join them together so there is no fuel pump at all and still get max rpm for as long as I want. Not recommended to fly that way of course, but it does work.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

You do not have permissions to reply to this topic.