Have a boat ....taking in a lot of water any idea where its getting in at
Based on what we have for info, I would be thinking the engine itself is leaking into the bilge. Time to run it on the ear muffs (or even back in the water) and start looking for the leak. That's how leaks are best found.
...the silicone around the gimbal seems to be tight. ...
Yep. There's your problem. You MAY have other problems, but I can guarantee that you have a rotten transom. That is the ONLY reason someone would put silicone around the gimbal ring / transom assembly. Not good news for you I am afraid.![]()