Got cruise on it?
When you touch the brake, cruise will come off normally. If switch is screwed, it could kill the engine by backfeeding to ground.
Also, check the electric solenoid that sets up the carb idle, when ignition is turned on the solenoid will pull the linkage and add a couple hundred rpms to start engine and when turning the engine off, it will disengage solenoid and linkage to avoid run-on of engine. Engaging A/C also adds rpm.
Last edited by alittle1; 10-19-2012 at 12:51 PM.