I have an '05 Four Winns with a Volvo 5.0 GXI-E. I've noticed this season that the boat will fire right up when put in the water. However it will run for about 3 seconds and then quit. It is then hard to start, I have to pump it a bunch of times and have the throttle about 1/4 open in neutral before it will start. Last year it started like a dream every time and kept running. Any ideas? Thanks