This problem has baffled me. I can run full throttle for about 20 minutes then the bottom cylinder(of the 3) cuts out. I remove power to the motor via a battery switch...then reconnect power, start the engine and it is back to full power for a somewhat shorter duration. At some point the bottom cylinder stays out for good. The next day everthing is back to normal until I run full throttle for more than 20 minutes. What could it be? I've trouble shot the coils and they're good. It doesn't seem to be overheating. Is it the CDI pack, voltage regulator or something else. Has anybody ever had this problem? Any suggestions would help.