Prop advice for 150 Yam. 15 or 16P.? 3 or 4 blade?

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  • Prop advice for 150 Yam. 15 or 16P.? 3 or 4 blade?


    New to this group and I need help. I have worn out my 18P 4 blade Stainless PowerTech prop and bought a 14.5x17 Aluminum one. I hoped dropping in pitch would get me over 5000 rpm but that's all i get with either prop. I just added trim tabs wednesday and that helped me get to 33 mph at most around 5000 rpm whereas before it was only 30 mph. there was not much wind or chop on the bay. I'm planing much better with the tabs now but i'm not jerking anyone out of their seat either.
    Need suggestions for Stainless prop, please specify 3 or 4 blade, brand and pitch and links if possible. 2005 HS with 150 Yamaha four stroke. 12x9 Bennett tabs. 14.5 x 17 4 blade by Turning Point (Aluminum). Located near Galveston, Texas. TIA

  • #2
    Ken should be here soon ... but you really want to pitch it to be IMHO no more than 200 RPMs of the highest end of the max range, (1/3rd fuel & normal gear carried) regardless of what that final pitch # turns out to be. Remember that boats only get heavier as the season progresses ... more gear carried, more slime/growth on the hull, and thinner/hotter air/temps.

    FWIW, different V-hull of only 20-degrees deadrise, but on my 20' cuddy/WA powered by a DI 2-stroke 175hp I'm turning a SS 4-blade of 15" pitch prop. I still need to raise my OB 1 more bolt hole, but the results are outstanding in hole shot and cruise. I lose a little top end WOT speed by having the 4th blade, versus a 3-blade wheel, but I'm more interested in cruise efficiency than pure speed, where I clock/record all my numbers via a calibrated fuel computer, so I'm reading direct results in MPG.

    TIP - Using trim tabs and the fuel computer I find I can dial in 10% or better economy. Like if a slight chop off the port bow, I'll raise that side of the hull out of the slop by only using one tab or the one tab down more than the other. Yeah the boat runs a tad heeled, but the ride is even smoother than if level and I get a better fuel burn, as a dayum cheap Yankee I am ... With proper tab settings you too should realize an efficiency increase too!

    Whilst at headway speeds, I also trim the OB up so that the prop is at or above the bottom of the hull and I can see up to a 25% improvement in MPG or more (current dependent for me), but admittedly my OB is out on a bracket on a full transom boat, so that's why I'm still running it in 'clean' water. For that matter, I also run it there (less when going to plane or whilst planing) as it improves torque and performance in reverse by pushing the thrust of the water UNDER the hull and not against it.

    Boating peeve #7 - When boat owners with more $$ than me run their much more expen$ive boats with the 2 OBs trimmed all the way down and in against the hull tight ... only to complain that their boat sucks in reverse ... idiots ...
    Life is too short for an ugly boat!

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    • #3
      So, trim tabs actually made the boat gain speed.
      that is a little odd.
      And I would really expect that boat to be a little quicker then 33 MPH.

      Is that a Hydra Sports 212 Vector ?

      I'm thinking check motor height here. https://www.bandofboaters.com/forum/...gs-to-look-for
      And I'd probably go PTZ4 in 15 pitch. Its a little Powertech 4 blade that does pretty well.


      Ken Reeves
      [email protected]
      941-735-5808

      Comment


      • #4
        Thanks Dale. I'm leaning towards a 4 blade 15P too. Just not sure which one and if i can find a deal locally on a used one or not. I'm not sure what you mean by clean water. Are you talking about if the motor is jacked/trimmed up to high the water is "dirty"?. LOL what are your other 6 boating peeves ?

        Comment


        • #5
          thanks Ken . yeah i was porpoising bad when trying to trim up slowly to get WOT w/o the tabs. v the motor is in top hole so maybe i need to adjust. it looks like it was once in 3rd hole down. if i can avoid doing the motor adjustment that would be great. . im pretty sure ill get the ptz4 from you.

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          • #6
            It is a 212 Lightning Series. 2005 model.

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            • #7
              Originally posted by captainsnapper View Post
              thanks Ken . yeah i was porpoising bad when trying to trim up slowly to get WOT w/o the tabs. v the motor is in top hole so maybe i need to adjust. it looks like it was once in 3rd hole down. if i can avoid doing the motor adjustment that would be great. . im pretty sure ill get the ptz4 from you.
              As I offered in our PM's, I believe you have a prop and motor height issue.. That would explain why you are porpoising with very little trim. A good shop could change the height in no time.
              2019 Tidewater 252 CC Twin F150's
              2016 Tidewater 230 CC VF250 SHO- SOLD
              Mobile, Al.
              Dauphin Island, Al.

              Comment


              • #8
                If desired, you can try moving the OB yourself ... if the OB bolt pattern is 2 holes at the top and 2 slots at the bottom.

                With the boat on the trailer you can move it with your trailer and 2 or more helpers. Lower the trailer jack all the way down and securely block the wheels and under the OB lower unit, having it trimmed to match the transom angle. Remove the 2 top bolts and loosen the bottom 2 bolts, with a helper on each side; each ready with the bolt to go back in, with wrenches and sockets as needed.

                Then start raising the trailer slowly, which allows the transom to start moving/sliding down the OB transom bracket. Go slow! Now this might be a 'Rube Goldberg' method for sure, but I've moved many an OB this way, but admittedly no behemoths weighing > 500-pounds.
                Life is too short for an ugly boat!

                Comment


                • #9
                  As stated above, moving a Yamaha up is easier then others, because the bottom bolts are in slots, not individual holes.
                  I use a floor jack to do the same thing. but the trailer method works just fine as well.

                  Sticking a 4 blade on there will improve the way the boat rides for sure. getting the motor height correct will also improve it.
                  I'd do both.

                  Ken Reeves
                  [email protected]
                  941-735-5808

                  Comment


                  • #10
                    Thanks guys! I ordered my PTZ4 14.25x15P 4 blade prop today. I was able to use an old worn down prop to go offshore wed-thursday but was only able to do around 30-31 mph @ 5000 rpm. The whole trip was 134 mile. When i go top off the tank i'll let ya'll know my fuel numbers.

                    The link below is the prop i ordered. I can not wait to get it! Do i need a special thrust washer for this or can i use the one i'm using for the OFX18P I have?

                    Click image for larger version

Name:	117838119_10158360194141131_8509073883828816667_o.jpg
Views:	126
Size:	90.5 KB
ID:	92392 Thanks Ken!


                    https://propgods.com/shop?olsPage=products%2Fptz3

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                    • #11
                      you should be able to run the same thrust washer as your other powertech prop.
                      It just uses the stock Yamaha thustwasher.

                      Powertech is backed up right now, so its going to be a few weeks before they ship, but anxious to hear how it runs.

                      Ken Reeves
                      [email protected]
                      941-735-5808

                      Comment


                      • #12
                        I got my 15 pitch PTZ4 on yesterday. I am jumping on plane now and getting exactly 6000 rpm on a flat calm bay. My GPS says im doing 36-37.5 mph trimmed up to max before porpoising. I was kinda hoping to get 40 mph but i'll take it as I hardly do WOT for long anyway. I forgot to do any tight turns to see how much the cavitation improved. Overall im pretty darn happy. Oh and im staying on plane at low rpm and speed. which is good cause i like to cruise. thanks Ken.

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                        • #13
                          Glad to hear it ran well, thanks for the report !!

                          Ken Reeves
                          [email protected]
                          941-735-5808

                          Comment

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