I hope someone has encountered this before.
I have a new, 2009 350 Black Scorpion DTS CAT engine in a v-drive boat. I definitely did not heae this sound before, but when idling the muffler rattles loudly (the horizontal tube that funnels the two exhaust tubes to the exhaust pipes?). It seems to be associated with low RPMs, as when you start the boat it is at it's loudest, settling to a lower level at idle. When given gas the rattle disappears. It is unsettling to hear, and I would think that a loud rattle shouldn't be expected in a new engine. I took the boat to my dealer and they gave a look into it. They didn't know what was causing it, but said that everything looked fine.
Anyone have an opinion on what could cause this? Or if this is anything to think twice about?
Appreciate the help!