Re: Verification of 9.8HP Mercury 110 outboard motor s/n and year
Agree with James, looks to be a 1972 model with a phasemaker ignition.
You may have a difficult time finding a factory manual. A very good alternative would be Seloc's "Mercury Outboard - 1965-1991, 1 and 2 cylinder Tune up and Repair Manual".
Sold in print or on-line formats (from this site amoung others, with the printed version available at most boat dealers) for about $35.
A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)