I am about to take delivery of a boat with a 2004 90 hp Merc 4-stroke (not EFI). I have not yet seen the owner's manual but because this boat is about to be trailered to a fairly remote location, I'd like on opinion on whether or not I can do the yearly maintenance. I can do it on 2-strokes and have mechanical skills but I've never touched a 4-stroke - I know I have to change the oil, and I presume changing the lower unit lube is the same for any engine, but are we talking about fancy instruments or tools to do anything else?<br /><br />The engine has 100 hrs on it and the dealer says everything is done up to the 100-hr point.