I have some friends that can help you.-----But it takes more than one person.------Takes more than 1 million $$ -----Takes more than one button to start one of these places.
A proper test is done on a MERC-O-TRONIC magneto analyzer.-----I never check for ohms on coils.------If spark does not jump a 1/4" gap or more replace them.----If coils are cracked , replace them.
What work does the motor need ??-----In 1999 there were troubling times for OMC.-----May not find a 99 specific manual.----A 1997 manual would likely be the same.
If this motor had water inside on the bearings for 2 weeks you may have major rust damage on bearings.----Some will argue, but I think this unit needs to come apart for inspection.