Tohatsu 25 2 Stroke question....Need Mo' Power!!

Discussion in 'Outboard Maintenance' started by jbedul, Sep 7, 2011.

  1. jbedul

    jbedul I Love!

    So, I'm running a 2008 Tohatsu 25 2 Stroke with Merc Sea Pro badging...

    A fishing buddy with a Suzuki 25 3 cyl on a John Boat is tail-grabbing my Classic... :shock:

    We can't have that, CAN WE??? :twisted:

    After some research, I've found that making the 25 a 30 can be as easy as removing the restrictor between the carb and motor. I've also read that there is a timing adjustment necessary in some cases. Adjusting the timing is beyond my comfort zone, as a hack-mechanic.

    What I DO know, is that after removing the restrictor, my engine idled a good bit higher, so SOMETHING happened.

    I'll run it in the morning, and see if there is any gain on my previous 34 mph top end.

    Here's the question, to entertain me while I wait to run the motor and see for myself...

    Can I expect "real" better performance, and is this motor now a 30HP??

    If I could touch 36mph, I'd be safely out of my buddy's reach...Unless he gets a 40... :lol:

    If you've been down this road, please advise.
  2. cutrunner

    cutrunner Cert. Yamaha technician

    Brazilnut know the procedure. Maybe he can help. So let me get this right, youve got a "30" merc/hatsu on a 13' gheenoe? Nice!!!

  3. TheBrazilNut

    TheBrazilNut Guest

    He has a Gheenoe Classic w/ 25/30hp Mercury Sea Pro Motor. Change the Carb gasket. The timing should already be set to 25.

    I have seen people post about a 3mph increase.
  4. jbedul

    jbedul I Love!

    Thanks BN for the answer, and FlatsReaper, for the PM'ed link.. 8)

    Well, the jury is IN and the Tohatsu 25 to 30 Mod is a GOOD one.

    Looking back, I found that my boat (Classic) was running a top speed of 32 mph, with a Solas 10X10X4 stainless prop, and a CMC T/T.

    I'm running the boat standing, with Tiller Ext./Grab Bar.

    With a fishing load and me today, the boat is running a SOLID 34, and touched a max of 35 somewhere along the way, though it was not long enough for me to see it on the display..

    The Mod was VERY straightforward, and I didn't have to mess with the timing, it was already set at 25 deg. BTDC.

    All I had to do, was replace the carb gasket.  Rather than wait on a Tohatsu part, I found that the carb gasket from a mid 80's OMC will work just fine.

    Total Time:  10 Minutes
    Total Cost: $1.55


    Anybody got a nice used stainless 12p 3 blade??  [smiley=evil6.gif]