Marine: Boating, Sailing, PWC, GPS and Navigation - Engine Sputtering

I have a 1-year old Mercruiser Alpha1 4.3L (carburated) I/O engine on my '06 Mariah bowrider.

Now everytime I shut off the engine (after being warmed up), it sputters and "coughs" for a good 15-20 seconds before finally shutting off. Almost immediately you could smell gasoline fumes coming off the enclosed engine compartment. I started experiencing this problem the last couple of times I've taken the boat out, after aproximately 50 total engine hours.

What could be causing this problem?

Any suggestions are greatly appreciated. Thanks, Andy

your engine is dieseling.... a condition caused by the ignition of fuel due to compression rather than a spark. There are a number of conditions that can cause this ranging from too high an idle speed - to a carburator not closing completely when shut down - to incorrect timing. Do a google on the subject for more details and possible fixes.....

Thank you very much for the info thezster. Ill google it to see what I come up with. On a good note, I just find out the engine's still under manufacturer warranty so I will schedule a service appointment to have this problem checked out.

I do appreciate your input/Andy