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What is the correct pitch and diameter for the 1990 2755 with 5.7 4bbl. Alpha 1-gctid403170

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    What is the correct pitch and diameter for the 1990 2755 with 5.7 4bbl. Alpha 1-gctid403170

    Any ideas? Top end is 25-30 mph, tough to get on step.

    I found it was better to call a local prop shop. You can tell them the type of boat, which engine/outdrive combo what you have on it now, how fast and the gph useage, and the rpms you are reaching. They will give you a variety of props to choose from depending on the numbers (in my case on my Suzuki outboard I ended up going to a 4 blade to get me on step faster)
    Boatless at this time

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      The only way to know what you should use is to start from what you have. This is what any prop shop will tell you.

      What RPM do you turn at full throttle?

      What size is your current prop?


        I have the same engine/drive. A wide body boat but right around the same length I think. I run a 16 inch diameter with a 14 pitch Mercruiser aluminum. Sometimes called an elephant ear because of the big surface area. You may be able to spin a 16x16 because of your 8 foot beam. I could but my wot was only 4100.

        I cruise 25 mph (gps) @ 3800, wot 4400 probably around 30ish.

        Its a great prop for low speed handling as well, runs the boat nice and slow @ 600 rpm.


          Its my buddys boat, It does have the "elephant ear" blades, Ill have to check what his WOT rpm is exactly. He was concerned that it was a bit more prop than his boat/engine could handle. Ill get the size when I get a chance.

          Thanks for all the help.



            The way to tell is whether the boat gets to the max RPM range when it is at full throttle with a normal load. If not, how much is it off? Typically each inch of pitch is around 200 RPM. The max RPM range is normally listed on the engine.