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12v 71-n fuel consumption question

Discussion in 'Engines' started by dennismc, Nov 9, 2017.

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  1. dennismc, Nov 9, 2017
    #1
    dennismc

    dennismc Senior Member

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    Have someone looking at my Stephens for possible purchase query came up as to injector size vs hourly consumption.

    Assuming 1400 rpm continuous, N65 injectors is there a fuel saving going to N55's ?
  2. Capt J, Nov 9, 2017
    #2
    Capt J

    Capt J Senior Member

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    It depends. But probably not. You will most likely have to cut pitch on the props so you have that cost in addition to changing the injectors. At 1400 rpms with N55's you'll go slower and burn the same GPM most likely. It would probably be exactly the same as running your current setup at 1300 rpms.
  3. Capt Ralph, Nov 9, 2017
    #3
    Capt Ralph

    Capt Ralph Senior Member

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    Fuel consumption vs injectors???
    Please do a search and see how many times this has been asked before.
    You want to save fuel, pull the throttles back....
    Don't screw with a good running motor that has been already been tuned to the props.

    It takes so many horse power to push a hull thru the water at X speed. Changing injectors just restricts the engine to a lower window.
    N55 vs N90 the same HP cost the same.
  4. baltimore bob, Nov 14, 2017
    #4
    baltimore bob

    baltimore bob Member

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    Mr Crapps has it right. Just keep the throttles off the pins (do run them up occasionally to clear the engines). A benefit is if you ever NEED the power, it is available to you.
  5. dennismc, Nov 14, 2017
    #5
    dennismc

    dennismc Senior Member

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    Thanks, I wanted the prospect to see an independent opinion as he felt there should be a reduction.