I have a 1988 bayliner 2155 sunbridge with a 305, points ignition. I have been having trouble with it getting on plane. It also idles rough and sounds like it loads up. The exhaust really stinks. I was out about a month ago and was towed in because the engine would not start. I found there was no spark, changed the coil and now I got it running and it still runs the same. I have changed the cap, rotor, points, wires, water seperator and checked the filter at the carb. Any ideas?