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  • X Star Prop question

    O.K. I know nothing about this stuff, but I have asked a general question on what prop to put on an '07 MCX X-Star, and I was curious if there are virtually unlimited options or there are just a few. My boat is coming with a 14.25 x 14.5(or 14.0)...is there really a difference between the two? Does the "cup" make a difference? Thanks for your help!

  • #2
    Yes, cup/size will make a difference. How much ballast are you running?
    sigpicwww.lauderdalelakesmarina.com

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    • #3
      OJ makes (at least) 2 choices:

      #472 14.25 X 14
      #473 14.25 X 14.5

      I'll be running the 14.25 X 14.5 on my '05 MCX X-star this year. I believe the newer X-star comes stock with a 14.25 X 14. Look at the stamped numbers on your prop when you get it.

      I'll post some performance numbers when I get in the water in about 4-5 weeks from now. I'll be running stock ballast plus about 1500 lbs.
      I was njskier on here.

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      • #4
        Where are you running the extra weight?
        sigpicwww.lauderdalelakesmarina.com

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        • #5
          (2) 400 lb. sacs in rear lockers
          600 lbs. lead under front seats. (approx.)

          This is what I'm going to start with, boat still in storage for about 4 more weeks.

          Question: should I fill the (2) rear on-board tanks too or leave them empty? MYMC says filling them may make the wake more "rounded" because their location is not that far back.
          I was njskier on here.

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          • #6
            We now offer another size for the MCX and 6.0 motor, 14.75 X 15.5 LC XMP EDGE 4-Blade part # 522. This propeller has replaced the 14.25 X 14.5 as standard from the factory. We also now offer a 14.75 X 17.5 LC XMP EDGE 4-Blade for the 8.1 set ups. We still have the 14.25 X 14 and 14.25 X 14.5 in production as well.
            Eric Johnson
            Johnson Propeller Co., Inc
            OJ PROPS 800-359-9730

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            • #7
              Interesting information.

              So for all 2008 X-star boats with the MCX and 6.0 motors come with the 14.75 X 15.5 LC XMP EDGE 4-Blade part # 522

              How is this prop with extra wieght in the boat? Pros or cons in comparision to the 14.25 x 14 prop?
              2008 Mastercraft 40th Anniversary X-star
              www.buckeyemarine.com

              2008 Touareg V8 Galapagos Metallic, Sienna leather, Execline, Technology pkg, Sports pkg,Class III hitch.

              2012 Volkswagen GTI 5dr DSG, Carbon Grey Metallic w/ Leather/Luxury, Technology and 18" Serron Pkg's. H&R springs, Unitronic Stage 2 Chip, Ultimate racing 3" downpipe w/200 cell metal cat, xenondepot 3k HID Fog lights.

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              • #8
                Correct, the 522 is now standard. The addition of extra ballast, depending on how much, may require propping down to the 14.25 X 14.5 or for extreme extra ballast the 14.25 X 14. The 522 runs very well even with some additional ballast.
                Eric Johnson
                Johnson Propeller Co., Inc
                OJ PROPS 800-359-9730

                Comment


                • #9
                  My plan is to have the fly-high system (2500 lbs) and at most 5-6 people in the boat... would this suffice? I don't necessarily need it to Snap out of the water... I will have the MCX
                  2008 Mastercraft 40th Anniversary X-star
                  www.buckeyemarine.com

                  2008 Touareg V8 Galapagos Metallic, Sienna leather, Execline, Technology pkg, Sports pkg,Class III hitch.

                  2012 Volkswagen GTI 5dr DSG, Carbon Grey Metallic w/ Leather/Luxury, Technology and 18" Serron Pkg's. H&R springs, Unitronic Stage 2 Chip, Ultimate racing 3" downpipe w/200 cell metal cat, xenondepot 3k HID Fog lights.

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                  • #10
                    Go with the 14.25x14 with the mcx and the fly high system!

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                    • #11
                      I would suggest running the boat with the 14.75 X 15.5 and see how it works with all you plan to put in it. If you find you need better low end then you could look at a reduction in pitch.
                      Eric Johnson
                      Johnson Propeller Co., Inc
                      OJ PROPS 800-359-9730

                      Comment


                      • #12
                        14.75 X 15.5 vs. 14.75 X 17.5? (for L18)

                        Originally posted by EJ OJPROP
                        We now offer another size for the MCX and 6.0 motor, 14.75 X 15.5 LC XMP EDGE 4-Blade part # 522. This propeller has replaced the 14.25 X 14.5 as standard from the factory. We also now offer a 14.75 X 17.5 LC XMP EDGE 4-Blade for the 8.1 set ups. We still have the 14.25 X 14 and 14.25 X 14.5 in production as well.

                        eric ,
                        i thought the 14.75 x 15.5 was for an L18 xstar. now i read that the 14.75 X 17.5 is correct prop. 50% of the time we will use only stock ballast but then the other 50% we will be heavily ballasted (4000 total pounds). also, factor in fuel consumption. which of the two would you use for this application?


                        "Tropic corridor, tropic treasure. What got us this far to this mild equator? We need someone, something new....something else to get us through" (James Douglas Morrison/The Doors)

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                        • #13
                          The 14.75 x 15.5 will work well with the extra ballast, better than the 17.5. Hard to say which way to go if you split the time with the ballast, the 15.5 will work better with the extra load than the 17.5 but should rev higher with the lighter load than the 17.5. Depends on which hair you want to split.
                          Eric Johnson
                          Johnson Propeller Co., Inc
                          OJ PROPS 800-359-9730

                          Comment


                          • #14
                            Eric...diameter, pitch and cup??

                            Originally posted by EJ OJPROP
                            The 14.75 x 15.5 will work well with the extra ballast, better than the 17.5. Hard to say which way to go if you split the time with the ballast, the 15.5 will work better with the extra load than the 17.5 but should rev higher with the lighter load than the 17.5. Depends on which hair you want to split.

                            Eeric,

                            thanks for the reply. i think i understand what pitch does and how it affects the boat. i do not understand what diameter does nor do i understand the definition of cup or what it does. would you please give me a brief high school definition /description of what effect diameter has on the engine and boat and what the definition of cup is and what effect it has on the engine and propulsion of the boat. thanks. i just want to understand.


                            "Tropic corridor, tropic treasure. What got us this far to this mild equator? We need someone, something new....something else to get us through" (James Douglas Morrison/The Doors)

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                            • #15
                              Pitch, diameter and cupping all work together. We can run lower pitch with larger diameter. The larger diameter loads the motor like it had more pitch. The lower pitch with the larger diameter allows for a stronger more aggressive low end.

                              Cupping essentially loads the motor as well, holding the water on the blade a bit longer. More cup equals less RPM. More cup can also help with low end power. Cup adds effective rake to the propeller. Cup also effectively adds overall pitch to the propeller. For example a propeller that is stamped 15.5, the overall pitch would be higher with cupping taken into account, as the stamped pitch is really a median of the entire prop without cup added. Keep in mind that not all propellers are pitched the same. One company may have a constant pitch propeller, pitch that is constant from lead edge to trail edge or they may have progressive pitch or even regressive pitch propellers. There are several ways to pitch a prop.

                              I see alot of guys get hung up on cupping too. Most of our propellers have a standadrd .090 cupping to .120. These number seem to work well with our pitch and rake distribution. More cup from .090 to .110, would lower the max RPM approx 200. Another thing to keep in mind is no two boats are alike. So performance of a propeller on your boat may vary if that same prop were to be run on a like boat.

                              Hope that answered some of your questions.
                              Eric Johnson
                              Johnson Propeller Co., Inc
                              OJ PROPS 800-359-9730

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