40 yamaha 2 stroke rpms and prop

Discussion in 'Prop Shop' started by millerrep, May 12, 2014.

  1. millerrep

    millerrep I Love microskiff.com!

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    40 hp yami on a 16' challenger, round chine almost flat in the back.  Running this: powertech REB3 10.5" DIAMETER, IN 13 PITCH, 3-BLADES,15  DEGREES AFT RAKE, CUPPED,

    Engine is high 3" above the bottom.  Works great turns no blow out, sticks period.  Holeshot is weak, RPMs are low,  5000 So, I take it to the shop, decide to lower the pitch to 11, from 13, and took some of the cup off the tips, bow is plenty high. 

    And almost nothing changed,  little better holeshot, but only 5100 rpms.  I say dang thought I'd get 400 500 ,  speed is 30, not trimmed much and a little tab.  Not sure this REB is going to get the job done.  I ll say the boat runs and handles great, but lugging a 2 stroke bothers me. 

    Thinking this thing might like the semi cleaver SCB3 powertech makes.  Looking for some comments on this 40 and propping.
     
  2. millerrep

    millerrep I Love microskiff.com!

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    Did get this info, 5100 with an 11 p prop would be hard pressed to hit 29 / 30 mph.  As this would be zero to negative slip with the 1.85 gear.   So the prop must be 12p or more still.  Thanks Ken  - Propgods.
     

  3. No Bait / Lures Only

    No Bait / Lures Only I Love microskiff.com!

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    Sell me that old Yamaha, since is underperforms so bad.. ;D