Prop help

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  • Prop help

    I own a 23cc Tidewater with a 4.2 Yamaha running a 15.5 X 17 Saltwater series II prop but max rpm are only 5300 any suggestions to reach max rpm around 5900?

  • #2
    Until Ken2 comes along, I'll give you my advice from owning a similar hull and motor. I tried the 17 SWS and also got about the same rpm as you.. The prop blades are just too big. The 17" Reliance series is a much better fit. When trimmed it gets up to about 5800. I also tried a 19" Michigan Wheel and it didn't do much for me and I tried the 21" Reliance which surprisingly worked fairly well with a light load but dogged out when loaded.

    Currently I have a Reliance 18" x (I think) 14 1/4" which runs just a touch faster than the reliance 17". Maybe 1 or 2 mph faster. For now, I'm sticking with that one.

    BTW, it's on a 200 HPDI and it came with the Reliance 17".

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    • #3
      What HP is your motor?
      I see the yamaha reports. F250 ran 51 mph with a 17 sws. https://yamahaoutboards.com/en-us/ho...2016-08-07_occ
      F300 ran 51 also, but maybe its a little differnet model. https://yamahaoutboards.com/en-us/ho...2017-08-03_occ

      Looks like both had the motors mounted in #3, which is almost as high as it will go. #4 being the highest.

      What GPS speed are you getting at 5300 RPM?
      Are you trimming the motor up much at wide open?
      what happens if you trim higher?
      How much Fuel, gear, people do you have on the boat for your 5300 wide open?


      The general answer to your question would be to drop down to a 15 pitch to get your RPM up.
      But would be better to know what your actual numbers are and what its doing.

      Ken Reeves
      KR@Propgods.com
      941-735-5808

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      • #4
        2017motor and boat 250HP, 3rd hole, 43mph reading with Yamaha digital gauge, trimmed up 2 to 3 people no more than 75 gallons of gas 100 to150lbs. of gear. Thanks Ken

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        • #5
          One more thing I'd check before changing props is your GPH at wide open.
          Should be burning right around 24 GPH. if your burning less, maybe the throttle position is not set correctly
          A bunch of guys posting their numbersd on the tidewater site.
          https://www.tidewaterowners.com/your...ight-t227.html
          Most seem to be running high 40's, low 50's.

          Ken Reeves
          KR@Propgods.com
          941-735-5808

          Comment


          • #6
            I thought of the throttle position but do not know how to adjust that?Any clue on adjusting.Thanks again Ken

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            • #7
              Well, you can just see what your GPH is at wide open. that will tell you if your getting it or not.
              23-24 GPH your getting full throttle on a 4.2L yamaha 250

              I don't know if you have fly by wire, or cables. SHO or Offshore


              Ken Reeves
              KR@Propgods.com
              941-735-5808

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              • #8
                I have cables and offshore model.

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                • #9
                  Parker Yacht on SIM on here could probably help you with the adjusting if you find your fuel burn is not what it should be at wide open.

                  Ken Reeves
                  KR@Propgods.com
                  941-735-5808

                  Comment


                  • #10
                    Thanks for your help will do.

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