1993 200 HP EFI, recently replaced spark plugs (NGK), water pump, adjusted oil injection. The engine runs rough at idle, in gear it gets worse and continues until I reach 1800-1900 RPM. Then the engine will run very well. Engine has lots of power, out of the hole and top end. I have had 2 dealerships work on it and neither fixed the problem. Both gave the plugs, water pump or oil injection as the reason for running rough but I still have the problem. I did not tell the 2nd dealership that I had already had it looked at. I did not want anything they did, or what I said to sway their troubleshooting. I live in a small town, on the lake and have to drive a coupe of hours to bring my boat to a larger Mercury repair facility. i am hoping to avoid that trip. Please help. Thanks