There absolutely is wood in the transom.
Drill a hole from the inside and check for rot. May have to drill several spots. The holes should be filled with epoxy if found to be dry.
One way I definitively found my leak was to put the drain plug in and fill the bilge with water. Obviously don't...
Had a similar issue on an older SR. Water was coming in around the transom assembly. Ultimately found rotten transom collapsed and loosened the transom assembly bolts/studs and caused the leak. Engine out, drive off, transom assembly off, and transom stripped of hardware inside and out. New...
I've found the engines need to be above 1k RPM to get any heat to the heater core. In reading the manual, our setup should have a circulation pump to lift the heater water to the core. I may install one this year. On another note, I use mine more without heat on during hot summer days.
It's hard to guess what went on with your neighbor's boat but it's possible corrosion of the cat was accompanied by spent manifolds and risers. What I meant was catalyst problems are rare by itself.
Catalysts on IO's is almost a non issue. I can't imagine they will be a problem on outboards. With that said, I'm a huge fan of outboards, but not on the back of a 35+' cabin cruiser.
Got my gen running today! Was not working when I bought it. Bad diode board. The small capacitor mounted on the old board was missing. Not a terrible job.
My opinion of them being quite loud was not at idle speed. Yes, at an idle, modern 4 stroke outboards are extremely quiet.
74 dB is impressive. No doubt the covers aid in that. I’d love to take a ride in one.