The dryer will start and run fine on like half of the settings ie the lower half of the dial. The other it won’t start but you can turn it and pull once you reach the spot it will start working. Also the knob feels funky like I have to press my fingers agisnt the dial and move it not with the knob. Thanks for any help I just picked this up used 
BDR1783, based on the information provided, it sounds like there is an issue within the timer itself if the unit is mechanical timer operated.