Friend brought me this engine to get running. Sat since 1982. It's got the quicksilver LU. Got it going, then put new points, condenser, wires, impeller, rebuilt carbs and fuel pump. Compression was 120 on all cylinders. Now it runs for a while , then quits.Today after going over everything I have done, fired up, ran awhile then quit. I put a primer bulb on the line, pump the bulb while it runs, keeps running. I have worked on johnnie/rides, but no master mech. There's a block off plate where a 2nd fuel pump apparently once was. Does it need a second pump. This engine goes on a hydroplane he raced as a kid and still has the boat. Wants to get it running again. Thanks for any help or suggestions to try. Chuck