[Code of Federal Regulations] [Title 40, Volume 24] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR205.157-3] [Page 134] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 205_TRANSPORTATION EQUIP MENT NOISE EMISSION CONTROLS--Table of Contents Subpart D_Motorcycles Sec. 205.157-3 Configuration identification. (a) A separate vehicle configuration shall be determined by each combination of the following parameters: (1) Exhaust system (engine): (i) Mufflers; (ii) expansion chambers; (iii) spark arrestors; and (iv) other exhaust system components. (2) Air induction system (engine): (i) Intake muffler; (ii) intake ducting; and (iii) air cleaner element. (3) Vehicle drive train: (i) Chain; and (ii) shaft. (4) Transmission gear ratio: (i) Standard transmission; and (ii) automatic transmission. (5) Cooling system configuration: (i) Natural air cooled; (ii) liquid cooled; and (iii) forced air cooled. (6) Category parameters listed in Sec. 205.157-2. (b) [Reserved]