motor problem.

I have a 250v 370w (sing/phase) motor with start problem, it has separate start cap, switched it on & sparks out of the back & it just hums trying to start, spin it by hand & it runs fine, I've replaced the start cap but still just hums, centrifuge engages/disengages on spin up & stop, just won't start with start cap, does anyone know what the problem might be, any help would be greatly appreciated, thanks

Dirty contact on the centrifugal switch

How do you know if the centrifugal switch actually works?? A motor that size i would just get a new one..

john..

As Tony says!!!

john..

Where are the sparks coming from?