No announcement yet.

So I put a 20hp motor on my sailboat.....-gctid388132

  • Time
  • Show
Clear All
new posts

  • So I put a 20hp motor on my sailboat.....-gctid388132

    Hunter 23.5, water ballast was full.

    The 9.9 yamaha high thrust moved the boat to 7mph.

    Every website said hull speed is the max speed, yet my eyes saw many trawlers the same length going way faster, and pontoon boats barge through the water all day at 15mph.

    And no one has ever put this size motor on a

    The 20hp motor gave me these results.

    1/4 throttle gave me 5mph

    1/2 throttle gave me 8mph (barging water, and not fuel efficient at this point obviously.)

    just a click past 1/2 gave me 8.5 mph and increased speed with more throttle

    I didn't push it anymore cause its still being broke in, plus I don't want to kill the transom.

    Sure, the rear end sunk down more and I made small wakes.

    I mainly got the motor cause the 9.9 had to run at 75%+ all the about wear and tear, this 20hp can run way lower, and sips the fuel at low rpm, after 2 hours I would almost say the 20hp is more fuel efficient than the 9.9 I had.

    I called Hunter and mercury before going through with this....because I've seen many hunters with 15hp motors and it ended up being that the 20hp IS the 15hp...just tweaked to get the extra 5hp....same weight, size...etc.

    Hunter wasn't worried about weight as much as they were worried about torque on the transom, they said to just throttle up slow obviously.

    But I went and had a custom aluminum bracket made, just to beef up the transom.

    All in all, I was able to push it a good bit paste hull speed and very capable of a little more, obviously just not efficient, I figure if I need to get back in a "hurry" I can push the extra speed and sacrifice the fuel.

    I assume hull speed is more limited to the big rounded bottom sail boats, mines fairly flat in the back and is trailerable.

    I love this motor over the Yamaha high thrust because its QUIET running low rpms on 2 cyl. vs. high rpm on 1cyl.

  • #2
    congratulations! Now you have a power boat too :drama

    If the motor fails you can use the sails as a kicker.......


    • #3
      Your Hunter 23 has a displacement hull. Most sailboats will become unatable and wobbly when overpowered with a high horsepower engine. Be careful how much you throttle up. Also consider the extra energy put into getting that extra 1/2 knot.

      MacGregor makes a 26 foot water ballasted hull that is capable of planing and taking advantage of a higher horsepower engine. If your hull is similar in design, you'll have better results.