I thought I had this problem licked, but it is back.<br /><br />My '58 7.5 idles smooth and runs strong, but after 4-6 hours of trolling it suddenly starts to cough and sputter and then it dies. Once it dies once, it is easy to restart but it will not rev up at all. Any attempts to increase the throttle (especially while in gear) will cause the motor to cough and die. Sometimes after resting for an hour or two, the engine runs normally for a few hours again.<br /><br />So far I've cleaned the carbs and rebuilt w/ a kit, replaced the float and set the float height correctly per the manual, checked the ignition system and replaced one cracked coil (other coil and points and condensers looked new), checked that points were clean and new and set to .020, and decarbed the motor w/ Sea Foam. The carbs are adjusted properly per Joe Reeves instructions.<br /><br />I suspected that the plugs were fouling so I replaced them with new plugs (J6J, .030) but that didn't help.<br /><br />The water pump is pumping a lot of water and the shaft and head are not overheating.<br /><br />I have the old style pressure tank and it develops plenty of pressure. Pumping the pump while the engine is dying does not help it keep running.<br /><br />Choking the engine does not help it keep running.<br /><br />I'm stumped here because the engine runs so good for a long time, then suddenly dies and runs crappy after that.<br /><br />Any ideas, guys?<br /><br />Thanks in advance,<br />Kev
