I have a 1989 Carver 3607 with twin 454's and when we launched this year there was water coming in the bilge big time. We discovered it was because the exhaust pipe/hose had come away from the exit hole in the stern. It seemed about an inch shorter than it should be and there is no way top stretch it. Anybody have any thoughts on this? And the area is almost impossible to get to...it's under the cabinetry and stuff in the rear cabin.
Hoses don't shrink. Is the flange fiberglass? Could it have cracked leaving a piece inside the hose? You probably will have to cut some access panels to get to it. Considering the age of the boat you may need to replace the hoses on both sides.
Exhaust hose is pretty standard and come in various diameter and length. Any half decent local supplier should have it or it can be ordered on line from a bunch of places like fisheries supply, defender etc
I don't know about shrinking but old and/over heated hoses do deform and could loose its former tight grip on a nipple. Every inch is pennies and the factory cuts the short side of the line when building boats. So it was probably guitar string tight when built. Possibly, when your techs replaced the risers, a lil extra tug - pull may have help loosen the hoses.
how did deal with this problem? I am up against the same issue and what a terrible spot to access! I am prob going to add through hull mufflers with an extended hose barb to reach the hoses.