Bertram 25. Help me evaluate transom now that keyholes are open

[biasbilt]

Hi,

I came across this discussion as I am currently working on my Bertram 25 flybridge.

I took the motors out and I'm swapping them for another set of 165 Mercruisers that are fresh water cooled.

I cleanup the bilge but the mounting holes for the front engine mounts are rotten out. I drilled a few holes and wood is bad and soft.

I will be cutting out the front engine mount area just as in your pictures and replace it with Coosa just as you did.

My question is, how did you mount the new engine mounts? Did you drill lag screws into the cossa after ? Or did you bolt through with some backing at the bottom.


See image below:
https://photos.app.goo.gl/2JWUtHraoqPWDzUX6

Don’t forget the front mount is only supporting 50% of the weight of the engine and any bouncing motion as you go through waves. All the torque that is twisting the engine to one side is taken through the vertical bolts from the bell housing to the inner transom plate, so your lag bolts don’t need to withstand massive pullout forces