How to get more speed from a 25hp yamaha

Discussion in 'Vehicles, Boats, Campers, & ATVs' started by SCDuck, Nov 30, 2012.

  1. SCDuck

    SCDuck Well-Known Member

    Other than the obvious changing props how can I get more speed. It's an '08 2cyl
  2. factory909

    factory909 Well-Known Member

    Smaller boat, I've heard of a few guys putting aftermarket reeds in. There is a place in Missouri that will hot rod the motor up for you.


    SUPERMAG Well-Known Member

    Those 2 hole Yamaha 25s are great little motors, they're justa little lacking in the torque department. I ran one for years, but sold it and bought a 3 cylinder. Aside from being faster, you'll be able to maintain that speed with a load.

    But to answer your question, I think you're limited as to what can be done. Reeds, disable rev limiter, maybe open up the airbox a little to help it breathe. Don't know if the exhaust can be modified to help the flow.
    Last edited: Nov 30, 2012
  4. Hud_AthensArcher

    Hud_AthensArcher Member<br>2012-13 Bowhunting Contest Winner

    Mount a Suzuki on the back of the boat instead. Or, get a CMC for it that way you can get more trim out of your motor, but Supermag is right they just lack torque and with any extra load you can just hang it up with those motors.
  5. shiftymcfive01

    shiftymcfive01 Super Member<br>2011 Turkey Contest Winner<br>2013

    had one. loved it. when I got ready to go a little faster I found a 3 cyl
  6. BodieDrake

    BodieDrake Active Member

    Hopped up reeds will make it cold natured so is it worth it? They are super dependable motors. I had one, can't tell you how many Suzuki and megas I passed. Not cause mine was faster but cause they were broke down. NEVER UNDERESTIMATE DEPENDABILITY
  7. factory909

    factory909 Well-Known Member

    SCDuck: What is your current setup?
  8. Razorback123

    Razorback123 Super Member<br>The Original BBDH

  9. SCDuck,
    I have the same setup with a 97' yam 25 hp 2cyl, love the dependability, starts on the second pull cold, and first pull after that, no mater what temperature. Just put a CMC PT-35 tilt & trim on my, and will be testing props this weekend. With the CMC I am getting GPS 31 MPH on WE 1542, with the motor only turning 5050 rpm, hoping to go down in prop size and get more rpm and speed. I would be happy to get 33-34 MPH out of it, if that happens, to heck with a 3 cyclinder and run what I got, and just kill ducks.
  10. Since I dont duck hunt......................yet....................What are you guys doing? Chasing the ducks down??????????:biggrin:
  11. Hambone

    Hambone Well-Known Member

    I do duck hunt.....more so than most, and this is by far the best question ever asked on this website......
  12. SCDuck

    SCDuck Well-Known Member

    I've got a 1552 polarcraft with a '08 2cyl yamaha with factory prop, new prop should be in today 10 1/8x 13 pitch SS.
  13. SC Duck,
    Not chasing down the ducks, just outrunning your buddies to the holes, sure does give you something to talk about! LOL
  14. shiftymcfive01

    shiftymcfive01 Super Member<br>2011 Turkey Contest Winner<br>2013

    that's funny and true. the only person I'm ever racing are the other guys I'm hunting with. "last one to the ramp buys breakfast!!!"
  15. browning5

    browning5 Well-Known Member

    Mine wouldn't turn enough rpm's with a 13 but did pretty good with a powertech sra 12 after I put a pt-35 on my 648 WE.

    SUPERMAG Well-Known Member

    Hey bama, empty hull speeds don't count. My 2 cyl would run 30-31 all day long unloaded with just me in it. But 2 people and gear, forget it. I didnt pick up a ton of speed going to the 3cyl, but I only lose a mile or two per hour loaded for bear. I figure I could gain that back and then some if I fork out the money for a cmc. But I can't justify the cost....poor folks gots poor ways
  17. birdman24

    birdman24 Well-Known Member

    like these fellas said, not much you can do with the 2cly, but they sure are solid, reliable motors. I have a 98 3 cyl and with just me it'll scream at a steady 39.5-7 straight on the transom, no t&t on a beat up xpress..maybe i can make room in the budget for an edge or WE in the next few years..
  18. clarkduck

    clarkduck Well-Known Member

    i sent heads and exhuast off of a 06 2 cylinder yammy to hydro tech. im getting 30 mph on a 1648 we during the summer with trollin motor and fishin gear. thats with the stock aluminun prop. havent had a chance to try diff. props yet. hope this helps.
  19. Panfish

    Panfish Well-Known Member

    Put my Suzuki dt25 on ur boat. We stuck it on my buddies 1552 and WOW!!!! Just glad we didn't have wings!!! 
  20. School Teacher

    School Teacher Active Member

    I had the same motor, 08 Yamaha on a 648 WE and would top out at 29-30 just me and lose about 5-6 for every person I put in my boat besides me. No kidding i was running 8mph :mad: one morning down river then got rid of it for a 98 Zuki and I'm running 35-36 and 24-25 with 4 grown folks.