Sounds like the starting switch is working based on what you said in the OP. If the switch were bad it would be likely that the start caps would blow. If you want to test put your amp clamp around the wire between the switch and the start cap.
Originally Posted by sw_ross
Did you test the motor unloaded?
If it coasts a long time after cutting the power in may need new bearings.
Baldor will also put grease zerks on the motor and shieled berings inside. People will start packing them with grease which can lead to troubles, which leads them to add more grease.
It is possible to fly without motors, but not without knowledge and skill. - Wilbur Wright.