California Code, Health and Safety Code - HSC § 43107

(a) The state board may, by regulation, adopt emission standards for new 1977 and later model year motorcycles registered or identified by the Department of Motor Vehicles which are sold in the state on or after July 1, 1976, or such later date as established by the state board by regulation.

(b) Motorcycles shall be exempt from the provisions of Section 43200.