I've had this issue every now and then since it was about a year old, so I've had it for about 50,000 miles now. It doesn't happen often, maybe 8 times in the bikes life. But lately its gotten bad. What happens is if I ride long enough to warm the bike up completely and turn it off, it will crank but won't fire up if I try and re-start quickly. Normally if I give it a little throttle it fires right up again. Twice now including this morning after getting gas it just wouldn't start on its own and I had to push start. It will push start every time, and the battery is in excellent shape. I literally just finished its major tuneup a couple hundred miles ago including valves, air filter, plugs, oil, coolant, brake fluid and cctl along with cleaning the throttle bodies out so it isen't a tuneup issue. My only guess is maybe the throttle bodies need to be sync'd?

 

Could be unrelated, but when my r/r was on its way out, the bike wouldn't start when it rectifier was really hot. After it cooled a couple of mins it would fire right up.

I replaced the r/r for other reasons and this problem disappeared.