I have a 2 stroke, 90 hp, Johnson outboard,2003 model. The boat was not winterized and had 1/3 tank of fuel last fall. I started the engine and ran about five miles when it started missing and chugging and losing rpms. It seemed like it could be fuel or ignition to me. I changed the spark plugs and the fuel filter, put in some good gas and some Heet. The boat runs pretty good up to about 3400 rpms but above that it starts to heave and miss. It idles smoothly and revs ok in neutral. What can a Non-mechanic check before taking it to the dealer for service. I would appreciate any expertise on what my issue may be. This is my buddies boat and he neglected it. Really, it is.
