2007 KAWASAKI EN500C7F Engine Problems

I WAS RIDING WITHOUT A PASSENGER ON AN INTERSTATE HIGHWAY AT NORMAL HIGHWAY SPEED (65-70 MPH) AND THE EXHAUST SUDDENLY POPPED A COUPLE OF TIMES AND THE ENGINE DIED WITHOUT WARNING. THIS IS EXTREMELY DANGEROUS AS A VEHICLE FOLLOWING ME COULD COLLIDE WITH ME AS I SLOWED. THE FIRST TIME THIS OCCURRED I WAS ABLE TO MAKE AN EMERGENCY EXIT TO THE SHOULDER OF THE HIGHWAY (ON A BRIDGE). PANICKED, I STOOD UP, POPPED THE FUEL CAP OPEN, CHECKED INSIDE THE FUEL TANK FOR GASOLINE. THE TANK WAS ALMOST FULL. I MOVED THE FUEL VALVE TO THE RESERVE POSITION, BYPASSING THE NORMAL FUEL FLOW. (***IMPORTANT: "I STOOD UP.") I SAT BACK DOWN TRIED TO START THE ENGINE AND IT STARTED AND RAN WELL UNTIL THE ENGINE DIED AGAIN SUDDENLY SEVERAL MILES DOWN THE ROAD. I THOUGHT THE FUEL TANK AIR VENT MUST BE PLUGGED BECAUSE EACH TIME THE ENGINE DIED...