1992 Bayliner 2050CX Mercruiser 4.3L inboard Alpha One gen 2 One of my exhaust shutters came off and fell down in the Y-pipe. I don't know how long it was in there but, it wore a hole in the pipe casting. Do I have to pull the motor to be able to replace it? I have the drive off, installing new bellows. The hole is slightly wider than a finger nail, and can be seen from looking straight down at it. I don't know if it can be plugged, being the temperatures it endures. Any help would be great. Thank you !!!