25hp Etec prop

Discussion in 'Prop Shop' started by mboeder, Jun 30, 2015.

  1. mboeder

    mboeder I Love microskiff.com!

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    I have a 25hp etec with cmc tilt and trim on a lt25 gheenoe. Factory prop is a 10.3x12 pitch and it had too high of an rpm. I put a tach on the boat and replaced it with a Powertech SRA 12 10" diameter. I am looking for a larger diameter because with the sra I am spinning 6200-6300 rpms!!! Way too much!!! Any suggestions? Looking at a Turning Point Express 10 1/8" 14p prop?
     
  2. mboeder

    mboeder I Love microskiff.com!

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    Ran a solas alum 4 blade 10" 12p prop and bounced of the rev limiter.... Stock prop is the best as far as rpm goes but I still feel it slipping at wot.
     

  3. RunningOnEmpty

    RunningOnEmpty I Love microskiff.com!

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    The Powertech SRA is breaking loose and slipping?
     
  4. mboeder

    mboeder I Love microskiff.com!

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    I ran the stock prop again wednesday. It ran 5400rpms with a 165lb buddy, 12 gallon livewell blacked out, my 175lb self and a yeti 35qt packed out. I lowered the motor last night and put the SRA back on. The cavitation plate was 3 inches above the bottom of the hull so i lowered it to 1 inch above.
     
  5. RunningOnEmpty

    RunningOnEmpty I Love microskiff.com!

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    5400 rpm is good considering all that weight. How fast was it going when you hit the rev limiter?
     
  6. mboeder

    mboeder I Love microskiff.com!

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    livewell, empty cooler and myself I've seen 30mph. I am hoping that I experience no blowout when turning. The motor WOT is rated for 5500-6000 and I would like to be around 5800-5900 area. I think the rev limiter is around 6300.
     
  7. RunningOnEmpty

    RunningOnEmpty I Love microskiff.com!

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    I checked your numbers and @ 6300 rpm's your prop was slipping 10%. You would need more pitch to compensate for that much slip. I'm guessing when you lowered the motor it reduced the slip and brought the rpm's down.
     
  8. mboeder

    mboeder I Love microskiff.com!

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    Rpms solo are around 5800-5900 with the SRA312 prop. Any turn and it blows out... Looking at larger pitch prop
     
  9. noeettica

    noeettica Well-Known Member

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    What is your Gear Case ratio ?

    You may just need some Cupping added ...
     
  10. noeettica

    noeettica Well-Known Member

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    WOW the Ratio is 2.15 You are going to need some pitch Not sure how much

    What are the splines on your prop ?

    I am looking for a 12 pitch SRA-4