Section 205.151 - Definitions(a) As used in this subpart and in Subpart E, all terms not defined herein shall have the meaning given them in the Act or in Subpart A of this part.(1)Motorcycle means any motor vehicle, other than a tractor, that:(i) Has two or three wheels;(ii) Has a curb mass less than or equal to 680 kg (1499 lb); and(iii) Is capable, with an 80 kg (176 lb) driver, of achieving a maximum speed of at least 24 km/h (15 mph) over a level paved surface.(2)Street motorcycle means: (i) Any motorcycle that: (A) With an 80 kg (176 lb) driver, is capable of achieving a maximum speed of at least 40 km/h (25 mph) over a level paved surface; and(B) Is equipped with features customarily associated with practical street or highway use, such features including but not limited to any of the following: stoplight, horn, rear view mirror, turn signals: or(ii) Any motorcycle that: (A) Has an engine displacement less than 50 cubic centimeters;(B) Produces no more than two brake horse power;(C) With a 80 kg (176 lb) driver, cannot exceed 48 km/h (30 mph) over a level paved surface.(3)Competition motorcycle means any motorcycle designed and marketed solely for use in closed course competition events.(4)Off-road motorcycle means any motorcycle that is not a street motorcycle or competition motorcycle.(5)Acceleration test procedure means the measurement methodologies specified in Appendix I.(6)Acceptable quality level (AQL) means the maximum allowable average percentage of vehicles or exhaust systems that can fail sampling inspection under a Selective Enforcement Audit.(7)Acoustical Assurance Period (AAP) means a specified period of time or miles driven after sale to the ultimate purchaser during which a newly manufactured vehicle or exhaust system, properly used and maintained, must continue in compliance with the Federal standard.(8)Advertised Engine Displacement means the rounded off volumetric engine capacity used for marketing purposes by the motorcycle manufacturer.(9)Category means a group of vehicle configurations which are identical in all material aspects with respect to the parameters listed in § 205.157-2 of this subpart.(10)Class means a group of vehicles which are identical in all material aspects with respect to the parameters listed in § 205.155 of this subpart.(11)Closed course competition event means any organized competition event covering an enclosed, repeated or confined route intended for easy viewing of the entire route by all spectators. Such events include short track, dirt track, drag race, speedway, hillclimb, ice race, and the Bonneville Speed Trials.(12)Closing rpm means the engine speed in Figure 2 of Appendix I.(13)Configuration means the basic classification unit of a manufacturer's product line and is comprised of all vehicle designs, models or series which are identical in all material aspects with respect to the parameters listed in § 205.157-3 of this subpart.(14)Engine displacement means volumetric engine capacity as defined in § 205.153 .(15)Exhaust system means the combination of components which provides for the enclosed flow of exhaust gas from the engine exhaust port to the atmosphere. "Exhaust system" further means any constituent components of the combination which conduct exhaust gases and which are sold as separate products. "Exhaust System" does not mean any of the constituent components of the combination, alone, which do not conduct exhaust gases, such as brackets and other mounting hardware.(16)Failing vehicle means a vehicle whose noise level is in excess of the applicable standard.(17)Maximum rated RPM means the engine speed measured in revolutions per minute (RPM) at which peak net brake power (SAE J-245) is developed for motorcycles of a given configuration.(18)Model specific code means the designation used for labeling purposes in §§ 205.158 and 205.169 for identifying the motorcycle manufacturer, class, and "advertised engine displacement," respectively.(19)Model year means the manufacturer's annual production period, which includes January 1 of any calendar year, or if the manufacturer has no annual production period, the term "model year" shall mean the calendar year.(20)Motorcycle noise level means the A-weighted noise level of a motorcycle as measured by the acceleration test procedure.(21)Noise control system means any vehicle part, component or system, the purpose of which includes control or the reduction of noise emitted from a vehicle, including all exhaust system components.(22)Noise emission standard means the noise levels in § 205.152 or § 205.166 .(23)Noise emission test means a test conducted pursuant to a measurement methodology specified in this subpart.(25)Serial number means the identification number assigned by the manufacturer to a specific production unit.(26)Tampering means the removal or rendering inoperative by any person, other than for purposes of maintenance, repair, or replacement, of any device or element of design incorporated into any product in compliance with regulations under section 6, prior to its sale or delivery to the ultimate purchaser or while it is in use; or the use of a product after such device or element of design has been removed or rendered inoperative by any person.(27)Test vehicle means a vehicle in a Selective Enforcement Audit test sample.(28)Tractor means for the purposes of this subpart, any two or three wheeled vehicle used exclusively for agricultural purposes, or for snow plowing, including self-propelled machines used exclusively in growing, harvesting or handling farm produce.(29)Vehicle means any motorcycle regulated pursuant to this subpart.(30)Warranty means the warranty required by section 6(d)(1) of the Act.45 FR 86708, Dec. 31, 1980, as amended at 47 FR 57720, Dec. 28, 1982