Transom Support?

Discussion in 'Boat Repair Help' started by Mr.T, Jun 8, 2006.

  1. Mr.T

    Mr.T Active Member

    I noticed the other day that the bolts holding my new 115 Yamaha 4-stroke that I had installed a few weeks ago are sort of "sucking in" the interior side of the transom - not sure if they just over-torqued the nuts when tightening them or what's going on. I'm also not sure how the transom is built - it sounds hollow when you knock on it, but I'm sure there's something inside for support, maybe honeycomb or something like that.

    (Now, before anyone gets started, the boat is a 2005 18 ft Xpress aluminum fishing boat, with all-aluminum transom. The boat is rated for 115 hp. And the 4-stroke is only 65 lbs heavier than the equivalent Yamaha 2-stroke. So it's not an issue of weight...)

    I'm wondering if it'd be useful to get some aluminum bar stock and double up on the inside of the transom? There's a support rib welded to the transom between the bolts, so if I added a chunk of thicker aluminum, it'd have to go vertically betwen the top and bottom bolt. I"m thinking a piece of 3/8" by 4" stock would really strengthen things.
  2. ka_c4_boom

    ka_c4_boom New Member

    i dont see where that would hurt ,i have 3/4 plywood on mine and it needs to be changed , might wait for better advice or go to the boat forums to see what you can find out on your own

  3. three_rivers

    three_rivers New Member

    Tupelo Ar
    I'd run it a few more times and see if they got worse. If it did i'd talk to the factory or dealer about an issue like that. It very well could of been over torqued since you just now noticed it. If it gets worse i'd talk to the dealer that installed the engine and or talk to express. I'm sure either would take care of you on a problem of this nature.
  4. timbo

    timbo New Member

    North Carolina
    YES,,,YES i would put 1 to 2 aluminum plates i had to do that to my boat i went to a metal shop and had them cut a plate ,,0f 1/2 aluminum,,you should be able to go to almost any weilding shop to get this,,,THANKS TIMBO:big_smile:
  5. duxsrus

    duxsrus New Member

    SW Ohio
    Yes there are easy ways to fix that but I would question why that is doing that on such a new boat first. Anyhow, I had to do that on my last boat which was a '79 hull that was just starting to show her age a little. I went with square galvanized perforated tubing. I think Home Depot carries it in the 1.5" inch size but I used the 2" size because I got it free. I just cut a piece the width of the transom and got longer bolts for the top two motor bolts and installed them through the bar. It strengthened up the whole transom. I would think you would have to get a pretty thick flat bar to equal the strength of square tube.
  6. RRaider

    RRaider Guest

    I read a post by a boat shop owner recently on another forum about this. Are the washers on your bolts about the size of a quarter? If so they need to be replaced, and he recomended a steel plate be installed across the transom with holes for the bolts for added support. Apparently he has had several boats come in for repair after serious damage.
  7. crome

    crome New Member

    when i bought my 1860 cc g3 last year,the dealer put 1/4'" thick 2 1/2"diameter washers on mine before he would let me take possession of the boat,he said it really wasn't needed but that was how they rig for the mid range 4 stroke motors.......crome
  8. tkoehler

    tkoehler New Member

    bass pro offers a transom plate for around $35