I'm familiar with two cycle motorcycles, and they're power band. Some
are really finicky and doggy untill you hit a certain rpm, then can be
almost uncontrolable. (Motocross) while some have less power yet a
wider range of usable torque.(Streetbikes) and some have the tuning
at the absolute bottom of the rpm ranges (trials bikes)

But concerning a v-4 johnson/evinrude etc. Is there a powerband where
you run a set range rpm for maximum efficiency? too little rpm labors
the engine, and too much gaines little except sucks more fuel?