i have a 1983 19.5 ft galaxy powered by a mercruiser 470 190 hp. runs great in neutral at all rpm levels but when i hit the water it runs great for about a minute or two gets up to speed and sounds great but then it hesitates and kinda stalls and i have to back off the throttle i get down to 1500 rpms ill run like that for a minute and punch it and it does the same thing thought it was a timing issue so i advance the timing at full throttle on the water and it gets better for a few seconds and then bogs down again. do i have a fuel problem or timing problem. it starts good and runs good for a short time. ive gave it a tune up and went to electronic ignation,plugs wires,cap,rotor, and a bottle of sea foam.
