I have a 1985 Johnson 90 hp VRO V4. I pump the primer bulb until it is hard, engage the idle throttle 3/4 and choke. It usually starts pretty easily. For the winter, I replaced plugs, changed lower unit oil and oil from tank, and fogged through the air intake right into the carbs. I took the boat out twice so far. First time, no problems. Yesterday, began stalling about 5 minutes into running. If i pump the primer bulb when it starts to shutter it will stay running. Seems like it uses the fuel that I pump in by hand through the bulb then runs out, and will not draw it's own fuel through the line. Should I use engine tuner spray? Change VRO pump? Where do I start to diagnose?