Engines starts fine and idles fine. When I rev up the engine in driveway on hose it is fine. Problem occurs on water when in gear and try to throttle up. It then stalls out. It will start up fine and idle fine but stalls when idling up in gear. Gas is from last year and I'm not sure how long since gas filter has been changed since I just acquired the boat. Could this be old gas problem or fuel filter? The gas was treated with stabilizer and Starbrite gas treatment.