Click for Burger Click for United Click for Alexseal Click for DeAngelo Click for Northern Lights

12v 71-n fuel consumption question

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

You need to be registered and signed in to view this content.
  1. dennismc

    dennismc Senior Member

    Joined:
    Jan 29, 2009
    Messages:
    1,037
    Location:
    Vancouver BC
    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

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    9,657
    Location:
    Fort Lauderdale
    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. rcrapps

    rcrapps Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    4,876
    Location:
    Jax FL
    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

    baltimore bob Member

    Joined:
    Sep 22, 2013
    Messages:
    292
    Location:
    Baltimore, Maryland
    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

    dennismc Senior Member

    Joined:
    Jan 29, 2009
    Messages:
    1,037
    Location:
    Vancouver BC
    Thanks, I wanted the prospect to see an independent opinion as he felt there should be a reduction.

Share This Page