California is one of the most hotly debated states for the laws on motorized bicycles...
From everything that I've read about the Cali laws, It's actually legal to have up to a 125cc engine on a bicycle. Anything over 49cc is supposed to wear a have a DMV plate & M1 drivers license, DOT helmet, full lights, mirrors, horn etc...)
It's supposed to be that 49cc & under doesn't require a helmet & other items, but most cops don't care about that & say that if the bicycle has any engine on it at all?, you have to comply with those laws.
So basically, if you just wear the DOT helmet, have the DMV plate & M1 drivers license & all lights, you are OK to ride it no matter what size the engine is; (up to 125cc).
California is very clear about the laws if you read them carefully.
There is absolutely NO mention of any cc limit for motorized bicycles,
just says
less than 2 gross brake HP
The 49 cc law is a fallacy and there is no mention of it in any
CA CVC codes.
If you have a 10 cc gas motor and pedals you are in the less than
2 hp motorized bicycle category.
There is also no mention of a 125 cc limit for motorized bikes.
A motor-driven cycle is any motorcycle under 150 cc and requires
registration and a M1 license.
The main difference between a motor-driven cycle and a motorcycle
is that a 150cc and less motor-driven cycle is not allowed on Freeways.
ALL gas powered 2 wheeler's in CA require a helmet with motorized bikes
needing a DOT helmet.
Even ebikes require a bicycle helmet and you have to be over 16.
Motorized bikes, Mopeds and Gopeds (scooters) require a M2 license but
of course a M1 covers all motorcycles, motor-driven cycles, and all the M2
classes as well.
Yes, it is just as easy to get a M1 as a M2.
Just because a lot of cops and DMV drones don't enforce or know these laws doesn't
make them not valid.