Honda BF130 prop on a 1997 Searay 175 restoration ?

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  • Honda BF130 prop on a 1997 Searay 175 restoration ?

    I'm currently running a 12.75x17 Honda 3 blade SS prop. I get 43mph @ 5900rpm with 3 adults and 2 small teens and half tank of fuel. I feel like getting the boat to plane takes longer than it should and having trouble keeping on plane at lower speeds. I'm in the process of restoring this boat and want to make sure the engine is running at top performance and the boat functions properly before dumping a bunch of money in it aesthetically. I have run some numbers through the Honda prop calculator and come with a 13.25x17 and 19 3 blade and a 13.25x15 4 blade depending on needs. This will be a family cruiser for skiing and tubing and the occasional fishing excursion. I'm thinking the 13.25x15 4 blade will give me the best performance for the needed applications. I know that even if I stayed with the 3 blade 17/19 the extra 1/2" diameter will give be better bite. What advice do other's have on this setup? Thanks..
    Last edited by athlon450; 06-04-2018, 12:49 AM.

  • #2
    when it takes a while getting up on plane. Is the motor turning 4000+ RPM but it takes a while for the boat to catch up to the RPM?
    Or is the motor only turning 2000 RPM or so, and slowly gains RPM as the boat gains speed?

    Ken Reeves
    [email protected]
    941-735-5808

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    • #3
      Yeah, as I throttle up the engine comes up fairly quickly but the boat is slow to plane off. We've moved the engine up one hole, when up on plane the boat runs 43-44mph @5900rpm. The anti-ventilation plate is running just above the surface and on hard turns from port to starboard I'm not getting any blow out when trimmed properly.

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      • #4
        I've just installed some trim tabs on the boat to help with the bow rise and try to get on plane faster. Just trying to see if s bigger diameter prop in 3 or 4blade would benefit. 17" in a 3 blade seems to be the proper pitch, if I go to a 4 blade I would need to drop to a 15" pitch in theory, correct?

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        • #5
          If the RPM comes up quickly during holeshot, but the boat takes a while to catch up, then you need a prop with more traction.
          A 4 blade can help with that, or a more aggressive 3 blade with more cupping.

          4 blade, I'd go RXB4 in 16 pitch. $375
          3 blade, I'd go NRS3 in 17 pitch. $319
          The only thing that would change this is speed.

          Are you getting speed from the speedometer? or are you getting it on GPS?
          The speedometers are notoriously wrong, and almost always read high.
          If you don't have a GPS handy, use a speedometer app on your cell phone.

          But if your getting 42-44 MPH on GPS, then I'd say you could turn those props.

          Ken Reeves
          [email protected]
          941-735-5808

          Comment


          • #6
            Gps, humminbird 798 si. The reason I ask about the 4 blade is I have access to a Honda 13.25x15 4blade ss. I might give it a try and see where things fall after the fact. Thanks for the help.

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            • #7
              yes, give it a try for sure !
              It is likely made by Solas, and they are often pitched a little higher then they are labeled, so let us know what it does.

              Ken Reeves
              [email protected]
              941-735-5808

              Comment


              • #8
                Will do!

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                • #9
                  Ok, I had a chance to run the new prop. The hole shot and the cruising characteristics are greatly improved. It stays on plane at slower speeds even pulling a tube. I was running 44mph(gps) @ 5800-5900 with the 3 blade 12.75x17, now I'm running 40mph @ 6000. With the 3 blade I could cruise @ 4500rpm @ 32mph, now I'm cruising @ 4900 at 32mph. The handling is better, I able to turn hard over to starboard and port @ 3200rpm motor trimmed up without blowing out. I very satisfied with the 4 blade 13.25x15 performance, just wondering since I'm now 6000 rpm @ 15" pitch do you think going to a 17" would still keep me in the rpm band and make up some top end speed.

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                  • #10
                    would be close.
                    you'll give up a little bit of the acceleration.

                    Be nice to try it, but you may find out you only gain 1 or 2 MPH, and you liked the acceleration more then the extra 2 MPH.

                    BUT, it may run 44 again but without slipping this time, you'd just have to try one out.

                    Ken Reeves
                    [email protected]
                    941-735-5808

                    Comment


                    • #11
                      3400# of boat, 40mph @6000 rpm with a 13.25 x15p 4 blade Solas Titan 4. What's my slip %? I keep coming up with infinite, when I put the numbers in. Thanks.

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                      • #12
                        Also if I go to a 17" pitch, I lose a 1/4" diameter. Is this a negligible loss or gain. Just curious?

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                        • #13
                          15 pitch, 2.0 gear ratio, 6000 RPM, 40 MPH is 6% slip. (very good)
                          http://www.heringpropellers.com/prop-slip/

                          The 1/4 inch difference in diameter won't make much if any difference. as long as your comparing the 15 and 17 of the same brand/model props.

                          Ken Reeves
                          [email protected]
                          941-735-5808

                          Comment


                          • #14
                            Sounds like I might be kicking a dead horse then.

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                            • #15
                              yeah, your numbers are pretty nice now

                              Ken Reeves
                              [email protected]
                              941-735-5808

                              Comment

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