Restarting problem when bike is above temp.

When the bike is warmed up everything is tighter so it is harder to turn it over and the starter needs to draw more amperage so if you battery is weak it will not have the ampewrqage needed but also if the starter has defective windings they may fail when hot but not when cold so you will need to do some more testing to see precisely what is the problem.

The starter may be dragging when hot. This is caused by an internal starter problem, Bearings or likely brushes. This can be repaired. Don't just replace it.
The stalling problem could be a fuel vapor lock. The fuel line gets hot and the fuel boils in the line. Rerouting the fuel line to a cooler place should help.

Sounds like the starter motor itself. Does the engine turn at all when you try to crank it?

sorry didn't actually see the post before my first comment, if it is only when the bike is warm or hot but not over heated I would suspect the same thing, faulty starter. "replace or rebuild"

Starter engages while riding Harley Davidson Forums Harley Davidson...

Hi
Some thing is expanding with heat or moving slightly to cause a dead short
if the solenoid click when the fuse blows I would suspect the starter motor brushes / wiring, insulating washer on lead from solenoid or the starter motors internal components

Ride Safe
Bike-Doc

If you did indeed overheat the engine to the point that is stuck, you would probably know it by the antifreeze being poured all over the ground. The bike would be really hot just sitting on it. It would smell like antifreeze and just smell hot.. I know, smell hot? but an engine that has been ran to hot has a pretty distinctive hot smell... It doesnt sound like an overheating situation if none of the above happened. A bike that is overheating will begin to loose power before it stops. LIke lacuna said, everything inside of the engine will start to expand from the heat and the piston will stick in the cylinder. Most of the time when this happens, the bike will cool off and restart. But, usually with problems. Warped or cracked head, cracked block, broken piston rings. These engines are aluminum and dont like to be overheated and warp really easy. If the engine is really hot, it will not turn over until it cools down enough. Im not saying it couldnt have overheated and then restarted without any problems, its happened before, but just not likely. But, if this is the case, take lacunas advice and change all of the fluids. Your oil will be nasty. Maybe get ahold of the previous owner and see if it has had any probems. It kinda sounds electrical to me. as long as the above overheating signs didnt happen. If you dont think it was overheating and it happens again, try to push start the bike to see if the engine turns over. even putting the bike in second or third gear just see if you can move the bike back and forth. If nothing else, you'll at least know its not locked up.

Any dtc's? Check fuel pressure and ignition spark...

This is going to be a problem with the starter. When a starter is getting a bit on the worn side, high temps will cause the electric motor not to engage creating the same clicking sound as if the battery was dead or had a bad contact.