Motorcycle Repair: S&S Carb problems?, chase trailer, fuel hoses

Question
I have a 2003 FLHT. It has an S&S "E" Series carb on it. I am having trouble with fuel delivery/volume--I think. One day I rode for about 90 miles, pulled over for some lunch & got back on the road about 30 mins. later. 8 miles down the road, my bike acted as if it was running out of gas. I had a half tank! I switched to reserve, no help. I did manage to milk it home although it was sputtering every 10 miles or so. I proceeded to rebuild the S&S carb, replace the petcock, R2 the ignition box, coil, spark plugs, plug wires, fuel hoses, vaccuum hose, and added an in-line filter. I was going to this anyway over time so I just decided to do it all at once. After that, bike ran fine around town, no issues. I loaded it up & took it to Virginia for a 1,500 mile ride with some friends. After 2 days & 800 miles with no issues, on the third day, it happened again--acting as if it were running out of fuel. I milked it back to the lodge & let it sit over night. The next day, I did 42 miles before it acted up again. Each time it acted up, my bike would just die after sputtering for a few hundred feet or so. It would never act up at the same distance. Sometimes it would go 10 miles, somtimes 55, sometimes 2! Each time it would die from lack of gas & after sitting for a few minutes, the bike would fire right back up. On that third day, I loaded it onto a chase trailer & took it into the dealer for repair. They got it to duplicate (Thank goodness) and tried to fix it. They said I had a dirty filter however I installed the brand new one 800 miles earlier. They messed around for a few weeks with it & my buddy picked it up today & drove it back to his place. 50 miles into the run, it broke down again! The dealership came & got it, started it up, rode it until it died again. They immediatly pulled the bowl off the carb & it was bone dry! They are at a loss because they said the float was working & all looked good inside the freshly rebuilt carb. Now then, I replaced or rebuilt everythin in the fuel/ignition system & the problem that I had before all that was done still exsists. I ahve one more twist to it & I'll let your brain go to work. One time when I pulled off the road because it died, my buddy noticed gas dripping from the expansion tank under the battery on the left side of the bike. When the stcok carb was on, it had lines going from the carb to the tank & returning again. Now that the S&S is on it, the only line connected to this expansion tank is the overflow from the tank neck. Why was gas dripping out there? Could my gas cap be bad, could there be some sort of pressure in the tank that is forcing gas up & out of the neck overflow? I am at a loss. I basically have two problems: 1) Float bowl runs dry & no gas is replenished until I pull over & sit a minute or two & 2) I have gas dripping for an expansion tank that seems excessive. we're chasing our tails on this one & the dealership as well as myself are frustrated. I have no confidence in my bikes ability to stay running. I appreciate your time & expertise, I hope you can help. Thanks alot, Dave.

Answer
Pulling over and letting the bowl get gas back in he carb leads me to think that you either have a (1) vaccumn problem at the petcock which keeps the petcock closed, (2) Your gas cap is not venting, (3) the float is sticking, or (4) you are getting vapor lock in the fuel line.
Try this, ride the bike with the gas cap off and see if you still have the problem. Let me know what you find.
Good luck and happy riding
Mike