Annual maintenance checklist for a used 90hp outboard before spring launch.

[AddisonWL]

I bought a used fishing boat last season with a 90-horsepower outboard motor that ran fine, but I want to make sure I'm doing the right preventative maintenance this spring before I put it back in the water. The previous owner was inconsistent with his records, so I'm planning to do a full service myself, but I'm unsure about the specifics beyond changing the lower unit oil and the spark plugs. For experienced boat owners, what are the critical outboard motor maintenance tasks you perform annually that are often overlooked by beginners, like checking the water pump impeller or greasing the steering linkage? How do you properly fog the engine for storage, and what signs should I look for in the old oil or plugs that might indicate a bigger problem needing a mechanic's attention?