Re: 5 HP mariner ID
Seloc's puts out a great "tune up and repair" manual for the small Yamaha built Mariners (which yours is).
It's called Mariner outboard tune up and repair manual 1977-89 covering 1 and 2 cylinder models. This site sells it for 30 bucks (which is a few bucks cheaper than the list at most other places).
It covers everything from simple maint all the way up to a complete rebuild - great manual (own one myself) and will walk you through carb adjustments or if needed, a rebuild of the carb.
A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)