I just upgraded the engine on my pontoon to a larger motor. It is a 1985 Mercury 75hp. I had the boat out on the water about 10 days ago and started and ran fine. The only issue I had was the pitch of the prop need to be changed. So this week I put a new prop on and took boat back to lake for test run. After backing boat back into water attempted to start engine but could not get it to start. It would cranking fine and it did start but then spudder and died. I did notice then when I tried to pump the primer ball it would never fill up and never got hard. Was wondering if it could be a issue with the gas link or the valve in the primer ball and one thing I have not checked yet would be the fuel line connection to the boat.