Whirlpool American Style Dryer

originally the motor was making a horrible screeching noise but not turning, then it would cut out,
after 5 minutes I could press the start button and it would do the same.
I tried turning the drum with door at the same time but it would not turn.
I fitted a new motro first time ever, It worked ok but after 2 loads it will only
turn if I give it a push exactly as if it needed a new capacitor.
I had the machine in bits and there is no capacitor.
I assume the new motor is faulty and advice welcomed.
Thanks