Do all 2 stroke bike have power bands?

Answer 1

A power band isn't an actual part, it's a rev range (or band) at which the frequencies of the pressure waves in the exhaust mainly as well as the intake more or less match up with the piston speed, or frequency, to give optimal cylinder filling and compression. This obviously will be the RPM range at which the engine will provide optimum torque and power if it is relatively high in the rev range.

The most important part in this is the exhaust system and whether it is properly tuned so the power band is actually noticeable or at an accessible RPM range is a whole different story.

For detailed explanation on how the expansion chamber works visit http://www.motorcycle.com/how-to/how-twostroke-expansion-chambers-work-and-why-you-should-care-3423.html

or get the book on 2 stroke engines by Prof. Gordon Blaire