I have a 2005 90hp 2-stroke mercury outboard. Took it for the first time on sea today. It was very hard to keep running at the docks. Kept stalling and needed high idle to keep running but managed to get it out on the bay. I haven't hooked up a tach yet but at full throttle i would estimate it to be running at about 2000 rpm. I don't believe the primer bulb was hard either. When I pushed in choke it would rev up for a split second. so i'm thinking it would be a fuel, fuel tank, fuel pump or clogged carb. What do you think is the problem?