Why won't a 2003 Harley Davidson Sportster 1200 start when hot?

All Harleys and many other modern bikes for that matter suffer from the same problem. The fault is in your electric starter motor. As it heats up with the engine and more so if the starter motor only has two brushes and not four, some soldered coil connections on both stator and rotor that have cracked due to thermal expansion, once hot they don't make good contact and for that reason the starter motor cannot produce its normal power. Normally it will all be fine if you allow your bike to cool down for a few minutes.... Of course, the problem remains and the only way to cure it is by replacing the starter motor itself or taking it to a specialist that can trace the cracked soldered coils and repair them. Best Regards, Spanish Flyer