Will a 4-blade prop reduce torque steer?

Discussion in 'Prop Shop' started by bostick29412, Aug 17, 2010.

  1. bostick29412

    bostick29412 I Love microskiff.com!

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    On the 14' skiff I'm finishing up (The Fidder), I've got a 1987 Mariner 20 hp that's pushing her along nicely. It's got the original aluminum 3-blade prop and I want to upgrade to Stainless. I don't have the exact size in front of me, I know it's a 10-spine prop.

    One question is, will a 4-blade prop reduce torque steer (it's a tiller-steer motor)?

    Toss in your opinions here on my best options.. thx.
     
  2. Brett

    Brett > PRO STAFF <

    Does your lower unit have a torque adjustment/zinc anode tab?
     

  3. RShrimp

    RShrimp I Love microskiff.com!

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    Tourque steer can be greatly reduced by trimming the motor.
    Play around with the trim rod. On my J12 I found that the 3rd hole provided very neutral steering. The PO had it set all the way down and it was a bear to steer.
    (Check the Simple (read cheap)stuff first!)
     
  4. The_Skiff_Shop

    The_Skiff_Shop Well-Known Member

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    The question is very general so I'll offer the same with the answer. A 4 blade prop will typically increase torque steer as a result of raising the motor for shallow water performance but your conditions may differ. ;)
     
  5. bostick29412

    bostick29412 I Love microskiff.com!

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    I honestly don't know! I don't have a manual for it.. should be the same as a Merc. of the same vintage. I'll check it out - along with the other suggestions.
     
  6. Brett

    Brett > PRO STAFF <

    Crowley Marine indicates that you should have an anode/adjustment tab...

    http://www.crowleymarine.com/mercury-outboard/parts/274_190.cfm

    That's part number 39, steering torque is eliminated by setting the tab to the correct angle.

    explanation of procedure...

    http://continuouswave.com/whaler/reference/manual18-25/operations.html#trimTab
     
    hawkeye likes this.
  7. bostick29412

    bostick29412 I Love microskiff.com!

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    You are the man, Brett. Thanks.