Rick,
3000-3500 RPM is cruising rpm for me, your definitely not even close to waking that engine up. Who did the pump work, do you know what impeller they put in the boat? I would check a couple things. First check to make sure your throttle linkage is setup correctly so that the carb is fully open when the gas peddle is mashed. Also make sure your secondary's are opening properly, most of us boat guys run mechanical secondarys but if you got a vacuum deal make sure they are opening.