No person shall modify the exhaust system of a motorcycle in a manner which will amplify or increase the noise emitted by the engine of such vehicle above that emitted by the muffler originally installed on the vehicle, and it shall be unlawful for any person to operate a motorcycle not equipped as required by this section, or which has been amplified as prohibited by this section.
RCW 46.37.537
Motorcycles—Exhaust system.
1977 ex.s. c 355 s 52.
Official source: Washington State Legislature. Reproduced from public-domain Washington statutes; confirm against the official source for the current text. Not legal advice.