Why doesd my mastermix stop under load ?

Hi, I have a mastermix MC130 that buzzes when i press the start button but it will not start the motor but it will start when i rotate the drum first, now this is almost certainly the start capacitor 10uf. The motor will run when this is done but goes back to just buzzing when put under load and stops. I am not familiar with this induction motor and need to know is the stopping under load related to the start capacitor or is the motor faulty too.
Steve.