Are transom hole patterns standard for outbord manufacturers

[PKKBEAU]

I am replacing the old and broken 1989 Evenrude 150 outboard on my 21' welcraft. I have removed the old motor and would just like to know if the mounting holes are going to be different when I purchase a new motor? Am I going to have to fill the old ones?

 

[Chris1956]

Re: Are transom hole patterns standard for outbord manufacturers

The std bolt pattern is four 1/2" bolts spaced in a rectangle. This pattern was adopted at different times by different manufacturers. I think your old motor will have the std bolt pattern.

Now the motor wiring is likely to be different as it changed in 1993.

 

[Georgesalmon]

Re: Are transom hole patterns standard for outbord manufacturers

Chris is right now-a-days they are all the same but I don't know just when that started.

 

[79Merc80]

Re: Are transom hole patterns standard for outbord manufacturers

Mercury was the last hold out on that issue and they started the transition in 1978 on the V-6's and 1984 on the inline 6's, 1986 on the inline 4'sw I think.

 

[Bob_VT]

Re: Are transom hole patterns standard for outbord manufacturers

If you google BIA Engine Mounting Pattern ....... you will see diagrams. Your motor is new enough where the holes should match up. While the motor is off..... check inside the bolt holes to see if wood is exposed and seal it up with epoxy or 3m5200..... just a layer smeared around in the holes will help.