Limited?
Low power (just enough horses to keep that big flywheel rotating; torque did the rest)
Slow (two speeds, stop and go) I think that you could vary the fuel valve a slight amount.
Heavy ( that flywheel alone must have been 100 lbs.)
Hey, we must remember that this fantastic invention replaced a set of oars, which were still carried , just in case, but were seldome needed.

My father had one of these when I was a child so I speak only from faded memory.