CS J12 with 15 hp

Discussion in 'Prop Shop' started by biochemken, Aug 6, 2012.

  1. biochemken

    biochemken Well-Known Member

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    I have a Carolina Skiff J12 with a 2005 Johnson 15 hp using the stock 9.5 x 11 prop on it. The skiff has middle and back benches with full front deck. I've got a trolling motor, battery, 6 gallon tank, plus gear, and my 200 lb self. Bottom line is that no matter how I shift weight around and play with the manual tilt on the motor, I can't get it to plane.

    It originally had a 20 hp, but after bring at the ramp for 2 hours for the last time trying to start it, I sold it for parts and replaced it with this. Marine mechanic has been all through this motor. We've rebuilt the carb, run Sea Foam treatments, and aside from being low on power, runs really well.

    Any thoughts on re-propping this setup, or is it a waste of time? I don't want to put too much more $$$ into it since the boat will be sold and replaced in the next couple of months, but I do want to have it performing as well as possible for its next owner.

    Thanks in advance!
     
  2. Rediculous

    Rediculous Boozle on...

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    A dulphin might help, unless it's just not enough engine.
     

  3. biochemken

    biochemken Well-Known Member

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    I had an Attwood hydrostabilizer on it, but took it off after it seemed to increase the amount of drag without having any real effect of getting it to plane.
     
  4. freshduc

    freshduc I Love microskiff.com!

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    a 15 hp should run that boat fine- you are pitched at the highest you can get for that motor tho. i have a 92 15hp 2 smoker- these motors are great but they dont make much hp at the bottom- might try a lower pitch with that much weight to get the rpms up sooner- i ran a 9.25 x 10 with 4 adults in a 10' zodiac and it scooted just fine- it did struggle to get on plane though. with me alone 210lbs it flew.
     
  5. jms

    jms don't let common sense get in your way

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    the small carolina skiffs - a little tough to plane - it's like pushing a piece of plywood through the water - smart tabs work well on these boats,to get them on plane...


    "low on power" ?
    could you define "low on power" ?
     
  6. biochemken

    biochemken Well-Known Member

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    Sure. When I say it feels low on power, it revs with plenty of RPM's and runs great, but at WOT, it feels sluggish and won't push enough RPM's to plane. With the replies I've had so far and other research I've looked at, I have to agree that I'm over-pitched on the prop. I'm leaning towards going down an inch on the pitch and going to a 4 blade prop.
     
  7. freshduc

    freshduc I Love microskiff.com!

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    Afterschool,
    I chimmed in a few days ago- I just took delivery of my 12ft fiberglass skiff on saturday.  I have been running a 9.25 x 10 on my 92 15hp evinrude with my old zodiac and was actually getting real high rpm's at WOT so I bought a solas 9.25 x 11 pitch 4 blade- when I ran the 11 pitch on my new 12' fiberglass boat i could not get it to plane with just me (210lbs) and a 3 gal gas tank (21lbs)- I was really dissapointed- couldnt get the rpms up - it just sat there and plowed- Later that day I took it back out with the 3 blade 10 pitch with with my wife, 2 kids and dog ( additional 200 lbs) and it went on plane with no problem-a little sluggish getting up but thats fully loaded and once it got up it did really well -  I was actually impressed on how well it scoots- I also ran it with just me and my oldest son (he's 50lbs) and it really moves (i would be suprised if it didnt hit high twenties) I havent tried a doel fin- the new boat is a tri hull in the front and flat midway to the back- Sounds like pitch is your problem as well- I would try a 9 pitch or if you want the top speed then a 10 with a fin on it. Hope this helps.
    you can get props on ebay with free shipping for about $65