I have had this happen on two different jeeps with Edelbrock 600 cfm carbs. They start fine in the morning or whenever the motor is cool. Two pumps of the pedal and they fire right up. If you cut the motor while it's hot and then try and start it immediately there is no problem. But if you let it sit for an hour and try and start it. No dice. You have to crank and crank and hold the accelerator to the floor to get it to start. It seems like the heat might boil the gas out of the carb, but then it would still be hard to start when cold. Anybody heard of this or have any ideas? Thanks in advance.