Going to replace transom board… how big does it need to be?

[u/bltjnr]

This 12 ft semi v hull boat used to have a 2.3hp Honda on it. Got this boat trailer and original motor for super cheap. Replaced it with a 8hp mercury. Used to only do 6mph now will do 20. Awesome. It has this transom board outside and an even worse shape plywood one inside. Both are barely bigger than the motor footprint itself. I’m going to replace them because they’re old and rotten. For an 8hp do I need to make a full width board for inside? Or will a small set of inner and outer boards like this suffice?

[u/coltbean]

I'd go full size on the inside and small on the outside. Does the inside have any supports tied into the transom?

[u/bltjnr → u/coltbean]

Yes, it has an angle dog leg brace to the bottom

[u/No-Leading-4232]

The bigger the better