Is it a lot more soot than you normally see on the boat and which side of the transom is it heaviest? BTW. I have seen many bad reliabilt rebuilt injectors right out of the DD box.
Both sides. Port engine just rebuilt. New injectors (port). Two had to be returned to s&s because they were stuck. 54 Bertram. Been told this is a characteristic of boat.
It might be......Do both engines achieve RPMs at WOT? How sooty are you talking about? Do you have a picture? It's not uncommon for boats with DD's and older mechanical diesels to get some soot on the transom......and even some newer ones do as well.......