#2 is pump kit, that is where I would start. Also if your motor is not oil injected see notes on filters it might have if not injected.
Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mercury Outboard OEM Parts Diagram for FUEL PUMP | Boats.net
You might do a search on that part number and find kit a little cheaper but these folks are usually in the ball park price wise. Did you by chance pull plugs and check them?