I have a Kenmore stackable dryer model 417.81142000. I have tried both 110 and 240 volt connections. It will hum, but does not start. I removed the dryer belt, and the motor turn freely. Any suggestions?

Will the motor run without the belt on? Will the drum turn freely? IF no to either of these, there is your problem. Note: without the belt on, there may be a switch that opens contact for the motor power, so you'd have to keep that active with the belt off. Its usually activated by the belt tensioner if there is one.