You should set up your throttle so that the carb is all but closed (1/16th-ish inch open) when throttle is fully down. Then, you use the trim to close the carb all the way. In most cases, during starting, flying and idle, the trim should be all the way up. You pull it (the trim) down to kill the engine. Then when you are done for the day - you should run it out of fuel or do the fuel line pinch to clear the engine of fuel. Anyone elses thoughts?