Mine has a rather heavy wheel on the compressor, with integral fan blades. I'm sure that it acts as somewhat of a flywheel.

But I did install a somewhat larger pulley on the motor, and have had absolutely no problems with it. The motor was wired for 110 when I got it, but I rewired it for 220 before even turning it on. I didn't have a big enough 110 outlet anyway.

There is no sluggishness upon startup, and it doesn't seem to be straining at all. And it hasn't tripped the breaker once.