27 Contender 200 Suziki's - Prop Help

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  • 27 Contender 200 Suziki's - Prop Help

    Hey guys, I just got my 27 Open back from a refit which included a pair of new 200 Suzuki's. After a fair amount of research here and on THT, I opted for a set of 4 blade 15.25" 22 pitch props. I have about 12 hours on it now. Generally speaking from a performance perspective things seem OK. At 4K I'm doing about 29, at 6200 about 48 which is plenty fast for me. The problem I'm having is the props seems to be slipping/ventilating so to speak. It's seems to happen more when I throttle up but does happen some when cruising. I'll watch the tach and can see it swing 400-700 RPM.

    So for my question,,,, after reading a bunch of threads it would seem getting a prop with more 'bite' might help,,, but I'm not sure. Would swapping my props for a set with a 24 pitch move me in the right direction??

  • #2
    As a start I'd check engineheight. Perhaps it's mounted a little high?

    Pitch: You'd probably want to be in that upper rpm-range. Lower rpms (at the propshaft) usually means lesser traction. I wouldn't go up in pitch/less rpm given your traction problems. The Suzuki DF150-200 gearratio doesn't help in that regard, so getting the rpms and engineheight right is important.

    Propchoice: The cheapest option would probably be to have a good propshop add some cupping to your existing props. New pair of props are expensive, but perhaps Mercury Enertia ECOs would work slightly better? I'd probably stay at 22". You maybe gain some rpms @wot compared to the OEMs (bringing you slightly over the engines max recommended range), but slip% are usually very low in the midrange on ECOs and it's probably a good idea to have the rpms up when cruising (compared to a 23" ECO). As long as you don't run flat-out all the time, you should be fine. Just be a little cautious with the throttle.

    I'd start with lowering the engines one hole down (up). The 4x15,25" OEMs are "big props" by default. If you really need a larger prop, PT LFS4 16"/4-blade are about the only option (together with Mercury Racing 5-blades - not sure about hub-compatibility). I doubt you need to go that extreme. Lowering the engines one hole and perhaps some quality metal-banging should be sufficient. If you don't like independent metal-banging, you have Mercury Bravo1 XC (Xtra Cupping) from Merc Racing. That should do the trick.
    Last edited by Ibiza; 09-09-2021, 02:56 PM.

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    • #3
      I'd start with alignment. It can make a surprising difference and may fix your issues without buying anything.

      You have a tiebar connecting the two motors.
      its adjustable.
      At the lower units, measure the distance between the motors at the front tips of the lower units. tip to tip
      then measure the distance between the motors at the prop shafts. center to center.
      Adjust that tiebar so the distance between the prop shafts is 3/4 of an inch SHORTER than the distance between the front tips of the lower units.

      then go run it, and let us know what happens.
      depending on how it runs, you may solve all your problems, or if its still there, we may want to modify the props a little or go with a more aggressive blade style.

      Ken Reeves
      [email protected]
      941-735-5808

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      • #4
        Thanks to both you guys for your thoughts. I don't want to modify these props just yet as dealer had previously said he would swap them for others if need be. I'm thinking I'd still like to try the 24's if the dealer will let me.

        As far as motor height I'm thinking I'm OK as I set it based on other 27's running these motors but I'm not ruling it out yet. I'll try to get a picture today when running to get your opinions on height.

        Lastly I just measured the toe (total PITA as it's on a lift LOL), it's 5/8" 'IN' currently. I'm going out to adjust later today and will run it and see. Will ley you know.Click image for larger version  Name:	Suzuki-height.PNG Views:	0 Size:	602.3 KB ID:	135810uld be sweet if this fixed it.

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        • #5
          Just got back from a quick test run after changing from 5/8" toe in to 3/4" toe out. Gotta say,,, seems a whole lot better. I'll hold on everything else until I get a full day on the water to make sure. A couple of videos we made on the test run are below. The number on top right on Simrad is MPH. Also,, in the second video I peg the throttles and we get to 6150-6200. I dont hear the motors cutting out so I'm assuming the rev limiter isn't engaging.

          Ken your sir are a gentleman and a scholar,, never would of thought that little of a change would make this much difference.



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          • #6
            Nice. I have a single engine, and am not used to think about toe - but is seems logical to find the right angle of attack Seems like the props don't ventilate when cruising @4000rpm. I notice that you don't trim the engines much in the video. Since the motors are new, it often takes some time getting used to their "behavior". When you're out, you could play some more with trimming. You'll probably notice that the props bites better and allows for more out-trim as rpms increases. On the other hand, their bite will decrease when rpms are down, and you'll probably have to trim down accordingly.

            I guess cruising will mostly be in the 4-4500rpm range, and if conditions are rough maybe even lower (3500-4000rpm). That's when/where bite and trim is important. To me the 22" props seems to be spot on. You might gain 100rpm-ish/1 mph when motors are fully broken in, but that leverage is nice to have when the boat is heavier loaded.

            I have a much smaller and lighter boat/single engine - so no apples to apples comparison. But prop-charateristics are often to some degree transferable between engines and hulls. Personally I run Mercury Revolution-4 on my DF150 and am happy with it. I often have to deal with rough seas, slow speed and need good bite/grip from the prop. I also tried a Bravo 1FS. Totally different props and handling characteristics. The Bravo 1 is sizewise similar to your OEM 4x15,25" where the Rev-4 is "smaller" with it's 14,5/8" dia. But if you look at these props side by side, you can se how much more cupping and "aggresiveness" the Rev-4 have (Rev-4 on right side).

            I'm not saying this is the right prop for your boat, but if you can get a loan or find it second hand, you could try a 23" pair.
            Attached Files
            Last edited by Ibiza; 09-12-2021, 11:40 AM.

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            • #7

              Great Video, thanks for posting it !

              Yes, a little change in alignment make a crazy difference in how the boat handles and drives. as well as the traction/ventilation issues getting up on plane.

              So watching the videos, the RPM seems pretty steady as you were getting on plane, so the 400-700 RPM swings are gone? or so far at least ?

              Let us know what you think after you get to run it more.

              I do like the Revolution 4's that Ibiza mentioned too, but they are hard to find right now. I do have a single 23 LH if anyone has a RH laying around.

              Ken Reeves
              [email protected]
              941-735-5808

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              • #8
                Well,, we went out for a few hours yesterday for a bit of fishing. Had a a chance to put some time on it. It's still slipping a bit at power up,, not what I'd call horrible but there is still an issue. Never saw anything like it with my HPDI's. Seems OK once up to speed and on plane though, it'd lock in and stay pretty even. I will say this,,, at 4000ish rpm at 30 MPH I was seeing 11 ish MPG. I'm happy with that.

                Would tweaking these props be of any value?? Thanks!!

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                • #9
                  Ran again yesterday afternoon,, more of the same

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                  • #10
                    you could have some cup added to those Suzuki props and likely solve the issue.
                    I use Rich Junker at Leading Edge Propeller, he does amazing work, and could definitely fix those props.

                    Ken Reeves
                    [email protected]
                    941-735-5808

                    Comment


                    • #11
                      Thanks Ken,,, doing a search I see one in Ellenton, FL and one in Mission, British Columbia. I assume florida is the right guy??

                      Update... found him on facebook. Thanks!!
                      Last edited by gtpvette; 09-28-2021, 11:11 AM.

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                      • #12
                        I've seen and learned over the years.... whatever Ken says....

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                        • #13
                          Yes, Ellenton
                          [email protected]
                          941 720 0710
                          He's hard to get ahold of, and works at his own pace, but does amazing work.

                          Ken Reeves
                          [email protected]
                          941-735-5808

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