Outboard swap--> Dimensions of transom holes

 Hi all, 

 

I am in the process of swapping my 2 stroke Yamaha 130 with a 140 Suzuki 4 stroke. I don't have access to the boat atm so can't go and measure but was wondering if mounting holes where universal on engines of similar size or am I more than likely going to have to drill some new ones in my transom? 

 

Also if i do have to drill new ones whats the best thing to do with the old holes? Sikaflex the shit out of them?  

 

Cheers. 


ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

They should be the same

Tue, 2021-01-05 21:29

 They are a BIA standard in use since the eighties, based on the old OMC pattern.

 

But if they are not, DO NOT just sikaflex them. This is just a general caution on looking after your transom.  If your transom is still good, it won't be for too long. Best way to plug substantial holes in timber transoms is to drill them out a bit, to get rid of any old sealant, then shape a hardwood plug from some hardwood dowel. Make it long enough to go all the way through, and a tight hammer fit. Then coat everything with epoxy, and hammer it home. if you don't have any specialised boatbuilding epoxy, 24 hour Araldite ( not the 5 minute stuff) does a very good job.  If you have to drill new holes, drill them well oversize, and seal the interior surface with more epoxy.  Thicker the better you need to really seal that surface, sikaflex doesnt do shit about keeping water out of cut, untreated wood. 

little johnny's picture

Posts: 5359

Date Joined: 04/12/11

Ranmar right

Wed, 2021-01-06 06:26

Should go through old holes . Only thing I would do different if by slim chance holes are different is seal holes and dowel with good resin ( not general purpose crap) . Would still do this prior to new motor going on .

Posts: 63

Date Joined: 28/04/13

 I had the exact motors

Wed, 2021-01-06 08:40

 I had the exact motors changed on my boat,same holes were used.

Posts: 48

Date Joined: 20/09/12

 Hey mate what boat and what

Wed, 2021-01-06 12:27

 Hey mate what boat and what performance differences did you see? 

Posts: 63

Date Joined: 28/04/13

 Hey mate Its a 575

Wed, 2021-01-06 14:00

 Hey mate 

Its a 575 fibreglass,performance wise the boat rode a tad better,got pretty much the same speed through the rev ranges, maybe not as quick out of the hole.The main reason to change over was the fuel,its cut the cost by over half.