GE washer wont agitate or spin

The washer fills and drains but will not agitate or spin,
I removed the front cover, the motor will spin with no belt, the tub turns free by hand, When I replaced the belt and turned it on, the motor starts to turn and so does the tub but then slowed an stalled. it will not turn again when I retried. Electrical smell from the motor and a humming noise. there is no grease or shavings of any type in the cabnet to indcate any other type of broken or worn part.
Can I assume this is a bad motor rather than the timer? or is the timer not providing enough power? would prefer not to buy the wrong part because if I do and buy the second part the expense is the same as a new machine. Can you help Thanks in advance