Use oversized flexible coupling?

Discussion in 'Inboards' started by Allweather26, Mar 6, 2024.

  1. Allweather26
    Joined: Mar 2024
    Posts: 1
    Likes: 0, Points: 1
    Location: Juneau, Alaska

    Allweather26 New Member

    I purchased an R&D flex coupling, but accidentally ordered one with a higher hp rating.

    Does anyone know the consequence of using it?

    Thank you
  2. C. Dog
    Joined: May 2022
    Posts: 181
    Likes: 54, Points: 28
    Location: Coffs Harbour NSW Australia

    C. Dog Senior Member

    Strongly suggest you send this question to the manufacturer as it is their baby and they seem dedicated to quality. They have probably encountered your situation several times. Best of luck.
  3. kapnD
    Joined: Jan 2003
    Posts: 1,304
    Likes: 414, Points: 83, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    Without a doubt, your boat will go faster while using less fuel!
  4. skaraborgcraft
    Joined: Dec 2020
    Posts: 416
    Likes: 131, Points: 43
    Location: sweden

    skaraborgcraft Senior Member

    How much higher HP? Given they are designed to take thrust and flex, I see little issue with it even if over rated, it will still be better than a direct coupling. As long as your alignment is good you shouldnt be putting any undue strain on the box.
  5. seasquirt
    Joined: Dec 2015
    Posts: 128
    Likes: 55, Points: 28, Legacy Rep: 10
    Location: South Australia

    seasquirt Senior Member

    Hi Allweather, if there is room to accommodate the larger size, and and shaft sizes match so you don't have to source adapters, it is a bonus. The slightly increased weight should make no difference if properly aligned, unless it is out of balance already.
  6. BlueBell
    Joined: May 2017
    Posts: 2,715
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    So it's over rated... more drag and more safety margin... embrace it.

    EDIT: How much more...?
  7. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    R&D makes couplings for 5-1500 hp. If you’re reasonably close, and it fits your existing coupling, I don’t see a problem.

  8. comfisherman
    Joined: Apr 2009
    Posts: 684
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    Location: Alaska

    comfisherman Senior Member

    As mentioned above the range that they cover is very broad. Would think only down side would be less flex.
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