Hells Bay Waterman, Yamaha 70hp 2 Stroke

Discussion in 'Prop Shop' started by reallyshallow, Jan 5, 2014.

  1. reallyshallow

    reallyshallow I Love microskiff.com!

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    Which prop would you recommended with an Atlas 4" jack-plate?
     
  2. TC

    TC I Love microskiff.com!

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    I have an '07 Gordon Waterman 18 with a 2 stroke 70 Yamaha and I'm currently running a PowerTech RED3R14PYM90. I also have this prop in a 13P. I've run both but get a little better top speed with the 14. Hole shot is great with both. Jeff at PowerTech confirmed these were the best props for my set up.

    Having said that, I do not have a JP, so I'm not sure if my response is of any help.
     

  3. reallyshallow

    reallyshallow I Love microskiff.com!

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    I'm now running a Powertech SCD4 17 pitch. So far the best I've seen is 38.1 at 5800rpm's, but that was with 3 people with a full load and a 21 gals of fuel.

    What kind of numbers are you getting?
     
  4. TC

    TC I Love microskiff.com!

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    You're getting better top speed than me. The best I've seen with the 14P is 35 mph @ about 5700 rpm and that's with a light load. How's your hole shot with that 17?
     
  5. reallyshallow

    reallyshallow I Love microskiff.com!

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    It's very good, the prop comes alive once I have the jackplate at 3"-4".  I'm considering getting a SCD3 18-19 and see how shes performs.
     
  6. reallyshallow

    reallyshallow I Love microskiff.com!

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    I was surprised how well the 70, 2 stroke turns this big prop.
     
  7. MariettaMike

    MariettaMike Wish'n I was Fish'n!

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    You're either trimming up to aerate that prop or cavitating badly because you're slipping 8 mph from theoretical speed of 46.1.

    You may find you will get better hole shot and overall fuel economy with a lower pitch prop that isn't slipping.
     
  8. reallyshallow

    reallyshallow I Love microskiff.com!

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    Jacked up to 4" and half trimmed. The prop is vented (so that helps on hole shot) and does not cavitate at all.  Theoretical speed at 5% slip (which is where I'm at) is 40mph.
     
  9. TC

    TC I Love microskiff.com!

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    Can either of you tell me what speed I should be seeing from my 14P at 5700 rpm?
     
  10. reallyshallow

    reallyshallow I Love microskiff.com!

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    According to the calculator 32mph
     
  11. TC

    TC I Love microskiff.com!

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    Cool. I'm doing okay, then, I suppose.