gonna need to find out if its fuel or ignition,, when it trys to die , try to put the choke on to see if it responds better,, if it quits like a switch is tuurned , quickly check for spark , fuel issue could be pick up in tank issue,, carbs , or fuel pump, sometimes it takes 2 or three times to get carbs right ,, electrical ,, check all plugs and connection , look for rubbed thru wires near engine and steering post ,, last could be stator