Must unlicensed motorized bicycles be electric?

A friend of mine built a pedal assist bicycle using a small four stroke gas engine. It's similar to this http://www.complexmag.ca/rides/2011/12/derringer-cycles-bespoke-motorized-bicycles

Presumably this would fall into the legal definition of a licensed moped and not e'bike. However, does the law say that unlicensed pedal assist bicycles must be electrically powered?

Now, what if someone rigged up a gas engine onto a conventional e'bike not to power the bike, but instead solely to charge the battery? Like this http://m.youtube.com/watch?v=k_VooEJdgoE&desktop_uri=/watch?v=k_VooEJdgoE

Yes, they must be electrically powered. You can buy conversion kits (such as BioniX, a Canadian firm) to turn a conventional bike to a legal pedal assist bike.