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  1. #1

    Question Low rpm at full throttle

    I have a mercury 40hp 4 stroke EFI (1000cc;4 cyl) with a 17 pitch propeller Black Max wth 3 blades and at full throttle I can only achieve 5000 rpm. The weight of the boat is 180kg and the boat is loaded with 2 persons. The recommended rpm for this motor is around 5500-6000. I feel that I loose some power with this low rpm. The actual speed at full throttle is 50km/h. What can I do to increase rpm. If I will increase rpm I will achieve a better speed?
    Last edited by stefancapatina; 06-29-2019 at 12:03 PM.

  2. #2
    Join Date
    May 2015

    Default Re: Low rpm at full throttle

    I don't think you'll make a big difference. For higher rpm either a smaller prop, less pitch, or some combination. To go faster, bigger motor or lighter boat.

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