That is a very broad topic in as much as laws vary from state to state, & there are an awful lot of small
engines out there, Kin ya narrow it down a mite?
No big deal your gonna have to pay a one time fee of about $20 for a M/B sticker The DMV will make up a vin# for you. No license or Insurance is required to ride a M/B under 4 Hp in CA.
Ya don't have to Smog a M/B, Moped, Scooter or M/C in CA.
I don't know who told you that you needed a Hwy cretified carb because ya don't..
What the H*ll is a under 4 HP Hwy certified carb anyways?
Only new Motorcycles or Scooters need to have CA. Emission standards for them to be sold in CA. After ya buy your M/C you can take all the emission stuff off (AIS and an Evap canister) if ya want because ya don't have to smog it.
If ya buy a bike from out of state that don't have emission standards ya don't have to have emissions AIS and Evap put on it to bring it back to CA.