I have a new 2006 383 MPI Mercruiser engine that sat crated for 4+ years. I installed it in my boat last month and after what I thought was a reasonably thorough pre service, started and ran it. Aside from lots of problems with the power steering that necessitated the replacement of both the ram and the pump, the engine ran real nice. This past weekend while out for a short cruise it suddenly began running like it had water in the gas. I managed to limp home (5 miles) at 1400 RPM and pulled the filter. The gas was clean. Not really surprising because the tank is new and the high test fuel was fresh. I changed the filter and reprimed. Engine started but very rough. Starboard exhaust was noticeably different from port. Shut engine down and pulled the plugs. All appeared almost like new. Did a compression test before reinstalling the plugs and got 185 to 190 which is good. Now the engine wont start at all. It only has 5 hours on it. I am very old school in terms of engine knowledge and dealing with problems and this engine has a mess of electronic stuff that is over my head but I do have spark and there is fuel up where you would attach a pressure tester between the 2 fuel rails. No alarms sounded during any of this so I assume there will be no stored error codes. Does anyone have any suggestion what I have had go on here? The boat is in a remote area on an island aprox 7 miles from mainland. Generally speaking, the local service resources are very limited in expertise so I am hoping this is something I can solve and cure with your help. I am thinking that possibly the injectors are plugged. How hard are they to pull and clean? Any and all input will be greatly appreciated.