I had one of the 89 Black Max's that would stumble and not go to full power from a dead stop until the boat was in motion for some time, then it ran fine...<br /><br />Well, I took the fuel pump apart and the top gasket was broken. All of the diaphrams were very 'stretched out'. The top one may have had a pinhole leak in it. I changed them out, put in the new check valves, and took the boat out for a test yesterday. Boat now leaps out on plane, and I can hit 5900 RPM instead of 5600, giving me a mile an hour or two...briefly broke 60, to 60.3. Before, it was right at 59. Anywho, that's not important...what is is that it just accelerates smoothly now. It seems to maybe idle better as well. Still doesn't start like an EFI, though!