Took 3 year boat/motor renovation to river today for first run. Everything was perfect until we put the motor into forward. Nothing happened, except the throttle increased. No prop spin, no gear engage...nothing. Has tested everything 4 times in the past 2 weeks with the earmuffs on in the yard and everything was perfect then and seemed to work well in forward and reverse. Per the Seloc book, I tested the gear/throttle linkage and tightened the control cables, and everything seems to be moving to the right place, which makes me think it might be a problem down in the gearcase itself. There is no grinding noise, so I don't know if the gear is shot or not. I am lost to this problem and I am hoping that someone can give me some advice on this. Any help you can provide is hugely appreciatetd.