340 etx cat exhaust manifold

[Chad Mueller]

Had to get towed off the lake Saturday morning...

I've got a 2012 22V Launch with the 340 + cat with 50 hours on it. Has been running great up to now. On Saturday I was only out for about 10-15 minutes and heading over to the bay where I usually ride. Engine sounded a little odd as I slipped into neutral and I could smell some burning. Temp read fine and no error codes on the engine and I shut it down. Wouldn't restart after that. The starboard exhaust manifold was definitely hot - the decals were scorched and peeling off and the hoses leading into it (I assume coolant lines for the cat?) were bulging under pressure.

Boat is currently at the shop and they're tearing into it. Water in a few of the starboard cylinders and they're getting a new manifold in. At this point, they don't know the cause. Dieseling was mentioned, but I find that highly unlikely. Also, would I have roached the exhaust like that if it was water coming up through? Seems like it has to be a manifold failure of some sort that caused the issue.

Anyone else have a similar issue? Did a quick search on the board but didn't come up with much.

Will advise. Bummer being off the water on a gorgeous weekend and looks sketchy having it ready before the holiday.

Chad

[sydneyACE]

One hot exhaust manifold + bulging cooling line going into the manifold suggests that you have a blockage on that side.
Sounds like the blockage was preventing water from flowing out of that manifold which caused your issue.

Just a guess... let us know how it goes.
Good luck!