89 Marathon dies when warm, wont start

[Oak Grove Panther]

I have been fighting a similar issue with my 86 EZGO project.I knew I was getting fuel, I knew i was getting spark, but after about an hour of running it around it would not restart after i let off the pedal or would just die. My fuel filter was full, but it wouldn't go. I found that if I sucked a little on the vent tube off the carb it would fire up and run for several hours.Seemed I was cleaning it out a little after a rich mixture of gas I had in it. I leaned out the fuel and would pull a vacuum on the vent and it would run. I am going to remove and replace the tube and see if it works. Someone else on here said he put the factory plug in his and it fixed his. Might not be the answer but if you know you are getting good pulsing from your case I would give it a shot.