New Outboard turns to the right

Discussion in 'Bubba's Outboards' started by Mr.T, May 19, 2006.

  1. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Just got a 115 hp Yamaha 4-stroke installed on my 18-ft Xpress and took it out this afternoon for some break-in running. Love the extra power, the jury is still out about the 170 lbs of extra weight I gained going from a 60hp 4-stroke to the 115hp.

    I found out real quick that if I let go of the steering wheel, it'll go hard-over to the right in about a half a second - in other words, the engine pulls to the right when going straight ahead and if you let go of the steering wheel, the engine turns to the steering wheel stop.

    Suspect there's a problem with the way the anode/trim tab is adjusted on the lower unitbut not sure how to fix it. The trim tab is already adjusted to the right (as you look at the motor from the rear) by about 2 "notches" on the lower side of the cavitation plate. Should it go the other direction?

    Will probably call the dealer on Monday but wondering what Bob and Bubba have for advice in the meantime?

    Also running a 19" pitch prop as per the Xpress factory recommendation, but find that the engine only turns about 5000 rpm at WOT. Guess I'll need to think about a 17" prop instead?
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Move your trim tab in the opposite direction that it is pulling. Pulling right move left and so on.
    Yep you need to drop down a prop size. You are making that engine labor. Don't be surprised if you have to drop two sizes. But get those RPMs up to snuff and go out and enjoy that thing.


    PS what is the recommended RPMs on that engine.
     

  3. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Remove the rubber plug above it. Insert a 12mm socket on a 4" extention & 3/8 drive ratchet, loosen the bolt, and adjust it all the way to the right.
     
  4. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Uh-oh. You guys are giving me opposite advice!

    The motor wants to turn the boat to the right. Do I move the trim to the right (as looking at the motor from the rear) or to the left?

    Bubba - The RPM range is 5500-6000.
     
  5. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Listen to bob on this because it has been so long since I had to adjust one that I can be wrong. He does this for a living and has a lot more experince then I do.:cool2:
     
  6. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Those trim tabs are actually torque tabs, to help compensate for engine torque, which will always turn your engine to the right, unless it's a counter rotating engine, in which case it's not really counter rotating, but the lower unit is.

    Some of those anodes are made with a curve on the right side to help cup the water and force the engine to help push the boat straight

    Setting that anode more to the right will help in holding the engine more to the left when looking at it from the rear.

    It's the prop your wanting to control the direction of.

    Water resistance on the right side will help force the motor/prop to the left, turning the bow to the left.
     
  7. catfishcentral

    catfishcentral New Member

    Messages:
    1,497
    State:
    OK
    Marty,

    I have a friend with that same motor on his 18 ft xpress and he runs a 21 pitch on his motor and it's in the 5500rpm range. I have no idea why two similar boats and same size motors would need two drastically different pitches(going to a 17 pitch) to achieve the same rpm. Could this be a part of the break in period for the motor? What about raising the motor placement on the transom. The holes on the transom the higher the motor the more rpm's I believe the motor will turn.
     
  8. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    Sounds like your not breaking it in like the manual states?
    Be careful. AS they can on a lot of motors plug it up and tell how you ran it.
    Good luck and enjoy the new motor. Also I bet it will not burn as much fuel as the old smaller motor.
    I know I can run mine at 4000 and still run as fast as the old motor did. And sips fuel.
    Pete
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill

    Good explanation Bob. Makes sense to me.
     
  10. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Thanks Bob - makes sense and I've adjusted the trim tab as you suggested. We'll see what happens next time out on the water.

    Also talked to the dealer and will be trading for a 17-pitch propeller next time I'm by his shop. It's surprising to me, though, that the recommendation for a 19-pitch prop on that specific engine and my specific boat came to me directly from the Xpress factory (I actually called them two times and talked to two different people).
     
  11. qball

    qball New Member

    Messages:
    150
    State:
    Odum, Ga
    I have the same problem with my outboard the only thing is mine is a 15hp johnson. there is no adjustment tab. I tryed to slide the motor to the right side about 1 inch from center to try to eas the pull to the right. After a little time of riding the old left arm gets a little tired.
     
  12. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    All is well now that I've adjusted the trim tab as recommended - really surprising that I had to move it so far, but if that's what it takes, that's what it takes.

    Thanks for the advice, Bob and Bubba!
     
  13. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Thanks Marty for the follow up. After Bob's post I got to thinking and some where in the back of this old feeble mind was a spark of memory that what he said rang true. :embarassed: He sent me a pm and told me how he remembered it.:big_smile:
    Glad it worked out and I can't Begin to speculate why it has to be turned so far.
     
  14. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Great! That's twice already this year that I've been right.

    I'm on a roll.:confused2: