I started the compressor and the motor was sparking, considerably, and when i shut it off it was smoking.
I plugged the air compressor in and there were considerable amount of sparks around the air cooling fan wheel. I turned it off and it was smoking.
What can the issue possibly be? How can I fix it or does a professional need to repair it?
Smoke after sparks
Sounds like burnt/burning brushes but cannot be sure as I have no idea of the compressor make or model.
You need to figure out what kind of motor (manufacturer) to try to get replacements.
Or, take it to a motor shop.
At least, let us know the make and model and maybe upload a photo or two?