I'm wondering if it could be a plugged pilot circuit.
I had my pilot get plugged about 200 yards from my truck. The bike acted like I fouled a plug. I pushed it back, put a new plug in.. and nothing.
Had bright spark, so I gave it another go at starting it. I found the bike would run with the choke engaged, but when I disengaged it, the bike would sputter out shortly after.
I took the float bowl off, pulled the pilot jet, blew it clean and reassembled. Bike ran great afterwards.