Why ignition switch? ignition switch usually energizes the starter solenoid, which starts the starter motor turning, if the starter motor is sticking in, nothing to do with switch. probably dirt in the winding screw, which throws the engage gear onto the flywheel, once started, the flywheel pushes the engage gear back down the screw, If it is the solenoid sticking, again dirt. Again if switch, switch would probably stick in the start position, key would not part return, to the on position.
SD, September 2011