Hi All,
In about 2002 or so, we we thought we had a fire on board as clouds of dense black smoke appeared from the aft cabin. We were motoring at the time.
It turned out that our exhaust pipe was joined by a piece of copper pipe which had corroded through.
We replaced the copper pipe with stainless.
I can’t remember offhand where exactly the join was, but it was in behind or under the aft heads.
It’s worth checking out your exhaust pipe, it may not be continuous.
Rob