I have a 1996 15hp gamefisher outboard that I just purchased a week ago. We saw it run and then after buying it took it to the river. It ran great for 15 minutes pushing my jon boat to a great speed. Then it started to bog down to where it shut off and wouldn't start back up. We figured it was a carb issue from sitting a while but the mechanic said it was the water impeller. We got the new impeller and it started up and ran great in a bucket. Once we took it to the lake, however, it would start and idle but shut off when put in gear and revved to slower than idling speeds. We then experimented with water levels in a bucket and found that it will run in gear at top speed when the water level is below the screw that says vent but will shut off when put in gear when the water is above the vent. It will idle and rev in neutral with the high water but not run in gear. In the lake it is impossible to keep the motor that high in the water and it ran at that water level when we first got it. I don't know much about outboard motors so any help would be greatly appreciated. Could the mechanic who fixed the impeller screwed the vent too tight when he put the bottom end back together? Once again, thanks to anyone that can help.
