Section 316.003(2), F.S., defines bicycle as “every
vehicle propelled solely by human power, and every
motorized bicycle propelled by a combination of
human power and an electric helper motor capable of
propelling the vehicle at a speed of not more than 20
miles per hour on level ground upon which any person
may ride, having two tandem wheels, and including
any device generally recognized as a bicycle though
equipped with two front or two rear wheels. The term
does not include such a vehicle with a seat height of no
more than 25 inches from the ground when the seat is
adjusted to its highest position or a scooter or similar
device. No person under the age of 16 may operate or
ride upon a motorized bicycle.”
That is the law in Florida.
The motor must be electric. Riding on the street with a gas motor on a bicycle in Florida with no DL is asking for tickets !
It is legal to ride it off road.
http://www.floridatrailriders.org/articles/croom.htm
It should have a muffler.
http://www.floridatrailriders.org/ftr_forums/index.php