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  1. #1
    Member
    Join Date
    May 2017
    Location
    Quebec
    Posts
    17

    Changed Prop - Lost RPMs

    So - had a very small ding in my aluminum Michigan Wheel Vortex prop - 14.25X21pitch

    Changed it to a Quicksilver Black Diamond 14.25X21Pitch brand new aluminum prop.

    Weird thing is, since the change, I cant get past 5000 RPMs now, still do 80kmh as before but the motor will not rev up to what it did before at 5500-5600 RPMs.

    Why? Same prop size and Pitch - Same speed but lower RPMs (does that make it more efficient).

    D In Mtl

  2. Member
    Join Date
    Jun 2012
    Location
    Sterling Heights
    Posts
    33
    #2
    Hello Dennismtl
    Yes... The prop would seem to be more efficient, (based on the data you provided). There are inherent differences between one propeller and another, nothing in mass production is exactly the same. I am more concerned with the RPM numbers as I would expect a small difference between props, (50 /100 RPM), but for sure not 500. If both props are in good condition, take them to a prop shop and have them check pitch and cup on each. Somewhere down the line someone may have reworked one.

    Robinr011

  3. Member
    Join Date
    Mar 2012
    Location
    Pelham, GA
    Posts
    2,003
    #3
    It’s not really plausible to directly compare on manufacturers prop pitch to another manufacturers. Heck, even comparing one manufacturer prop to a different model prop from the same manufacturer isn’t always apples to apples. You may could try a 19-20 pitch prop from Quicksilver to see if you gain any performance.
    Mercury 2002 200hp Carbed Saltwater
    OT566776
    2002 Cape Horn 22' Bay

  4. Member
    Join Date
    May 2011
    Location
    Spangle, WA
    Posts
    6,180
    #4
    Quote Originally Posted by leonreno View Post
    It’s not really plausible to directly compare on manufacturers prop pitch to another manufacturers. Heck, even comparing one manufacturer prop to a different model prop from the same manufacturer isn’t always apples to apples. You may could try a 19-20 pitch prop from Quicksilver to see if you gain any performance.
    ^^^^
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax