If it was properly winterized that included fogging the engine, you shouldn't have much to do or worry about. Not really familiar with that particular boat brand, but if you really wanted to be safe, pop the plugs off and squirt some oil on the cylinders first. I believe that you have the common 3.0 GM engine. If so, then the AC Delco PH35 will fit. It's a larger filter so make sure you got some room in the engine bay to mount it. Hopefully your carb. fuel bowl was drained, if not, then the fuel would have probably evaporated and left a nice coat of varnish in it. Might want to spray that with carb. cleaner with TCE. This stuff drys instantly and not leave any residue. Check the fuel bowl and see if it has any varnish on it also. I would replace the engine oil regardless, 4 years is a long time and 4.5 quarts of oil for that engine is cheap insurance. Pour some oil in the filter also before turning it over. I would hit the kill switch, make sure you got a good strong battery, and turn the engine over a few times to get the oil moving and the cylinders good and lubed. Then try and start it. Make take a few turns to get the fuel pumped back into the carb. because this engine uses a mechanical fuel pump. Once running, make sure you got muffs on the engine or the outdrive is in the water, and watch you temperature guage. If it starts shooting up past 160-180, kill the engine, you probably have a bad impellor in the outdrive. They do dry rot. The 3.0 is Mercruisers work horse engine and can take a lot of abuse.
