Prop sizing question

Discussion in 'Questions/Comments' started by Chuck Hunter, May 29, 2018.

  1. Chuck Hunter

    Chuck Hunter New Hydrodyner

    Joined:
    Sep 5, 2017
    Messages:
    3
    Location:
    Rhinelander/Sugar Camp, WI
    Boat Model and Year:
    17.5 Hydrodyne - 1990 w/1992 150 HP Evinrude Intru
    Have 1990 17.5 hydrodyne with 1992 - 150 HP GL 60 degree Evinrude. Present prop is 15 x 16. Hole shot is great but concerned about over speeding engine. Revs to 5700 RPM manual states 5600 RPM redline. Top end is seem low - low 40's. Anyone have suggestion, opinion or experience?
     
  2. jim

    jim Hydrodyne 18 Specialist

    Joined:
    Jun 14, 2006
    Messages:
    2,301
    Location:
    FL
    Boat Model and Year:
    77 Dyne 18 I/O converted to Outboard
    You are hitting rev limiter. The engine is not over-speeding, it will take that rpm and more all day. That is a great ski prop for a great ski boat. You don't need more speed for skiing. A 15x19 will give you more speed, but less pull.
     
  3. Chuck Hunter

    Chuck Hunter New Hydrodyner

    Joined:
    Sep 5, 2017
    Messages:
    3
    Location:
    Rhinelander/Sugar Camp, WI
    Boat Model and Year:
    17.5 Hydrodyne - 1990 w/1992 150 HP Evinrude Intru
    Had engine missing issues. Have them corrected, engine is running great. Now have issue with boat wanting to run bow down above 4000 RPM. Can get the bow up with excessive trim, but get ventilation issues and propusing issues. Have removed the cant wedge which helped. Motor is mount 1” high on transom. Running 14.5 x 19 - 4 blade. Still hitting 5700 @ WOT. Don’t believe the engine has a rev limiter since I have seen 6300 RPM on the course to getting the engine running correctly.
     
  4. Chuck Hunter

    Chuck Hunter New Hydrodyner

    Joined:
    Sep 5, 2017
    Messages:
    3
    Location:
    Rhinelander/Sugar Camp, WI
    Boat Model and Year:
    17.5 Hydrodyne - 1990 w/1992 150 HP Evinrude Intru
    Forgot to mention going to 14.5 x 19 prop has not hurt performance, hole shot with ski is better and to end has gone from 36 to 48 MPH.
     

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