my 2008 gz250 cut off on me while going 50mph....???

[Shearerforce]

Hello all...I just bought a used 2008 gz250 with 1890 miles on it and the guy took really great care of the bike. I have personally put 147 miles on it so far and have not changed a thing on it. Yesterday I was riding about 10 mins into the ride at 50 mph and the bike stutterrd and lost power a few times then completely shut off. The bike had been perfect prior to this happening. Everytine I have ridden the bike I have had no problems. I coasted to the side of the road and tried to start the bike again. It took a few tries but it started and idled fine. I started back on my way home and the same thing happened at varying speeds such as 30mph and 40 mph. After the bike cutting off about 8-10 times on the way home which is normally a 15 min trip I finally made it. I let the bike sit as it was very hot(motor) and I was worried I blew it up or something. I tried to ride the bike later that night around my neighborhood to see if it would do the same thing and it did. It shut off while gping slow and when I pulled the clutch in. I rode for about five minutes and it cut off about 6 times. I made it back home and parked it. I have not ridden it since. Any ideas on what this could be.....Thanks! Really appreciate any insight.