Motorcycle Repair: throttle wont respond when hot, harley dealer, 883 sportster

Question
mike,
my 2004 883 sportster (custom) xl wants to stall when i turn the throttle after its hot (after it runs about 40 miles)... it starts fine... it runs smooth for a while... but after it heats up in city riding and i try to start out from a stop light, the throttle doesn't respond... initially if i feather or pump it it'll work but once it starts doing this it just gets worse until it dies... the local harley dealer doesn't want to deal with it because it doesn't do it all the time and they're not willing to run it around until it acts up... as is, the bike is of little value because it's totally unreliable... anything i can pass on to some service people who think i'm crazy ? it's got about 2700 miles on it and began doing this at about 2400 miles... they looked at it (supposedly) and said there's nothing wrong with it ?!@#? it's still under warrenty and other than an oil change hasn't been touched... it's garage kept... thanks...
rick  

Answer
That is somthing that a dealer will not help you with your bike under warrenty! I think I would go to another shop and complain to harley main office. You can get their customer service number off the web.
there are several things that can cause this problem. Timing is off, ignition is about to fail, gas is vaporizing when the bike is sitting still like that, float is off in the carb, coil is getting to hot and startting to fail is just a few.
Good luck and happy riding
Mike