1974 40HP Johnson - Not Started for a couple of years?

[kamie]

I am looking at a boat with a 1974 40HP Johnson, the owner indicates the outboard ran "a couple of years ago" but no other info. I am trying to find out if they winterized it, or just let it sit. Either way, assuming I purchase the boat, what are my first steps on the engine. I assume, as follows
1. Change impeller
2. Change the lower unit oil
3. Change the spark plugs
4. ?? This is the part where I could use some help?

Thanks

[Bassmeister]

Rebuild carbs come to mind.