40 CFR § 205.166 - Noise emission standards.
(a) Noise emission standards.
(1) Exhaust systems and exhaust system components that are designed and marketed for use on any Federally regulated street motorcycle of the following and subsequent model years must be designed and built so that when installed on any such motorcycle which is in compliance with the requirements of subpart D of this part, they will not cause that motorcycle to produce noise emissions in excess of the levels indicated:
(i) Systems designed and marketed for use on street motorcycles other than those that meet the definition of § 205.151(a)(2)(ii):
| Motorcycle model year | A-weighted noise level (dB) |
|---|---|
| (A) 1983 | 83 |
| (B) 1986 | 80 |
(ii) Systems designed and marketed for street motorcycles that meet the definition of § 205.151(a)(2)(ii) (moped-type street motorcycles):
| Motorcycle model year | A-weighted noise level (dB) |
|---|---|
| (A) 1983 | 70 |
(2) Exhaust systems and exhaust system components that are designed and marketed for use on any Federally regulated off-road motorcycle of the following and subsequent model years must be designed and built so that, at the time of sale, when installed on any such motorcycle which is in compliance with the requirements of subpart D of this part, they will not cause that motorcycle to produce noise emissions in excess of the levels indicated:
(i) Systems designed and marketed for use on off-road motorcycles with engine displacements of 170 cc and lower:
| Motorcycle model year | A-weighted noise level (dB) |
|---|---|
| (A) 1983 | 83 |
| (B) 1986 | 80 |
(ii) Systems designed and marketed for use on off-road motorcycles with engine displacements greater than 170 cc:
| Motorcycle model year | A-weighted noise level (dB) |
|---|---|
| (A) 1983 | 86 |
| (B) 1986 | 82 |
(3) Exhaust systems and exhaust system components that are designed and marketed for use on any Federally regulated street motorcycle shall be designed and built so that, when installed on any such motorcycle which is in compliance with the requirements of subpart D of this part, and when both the motorcycle and the exhaust system are properly maintained and used, they will not cause that motorcycle to produce noise emissions in excess of the levels specified in paragraph (a)(1) of this section, for an Acoustical Assurance Period of one year or a distance of 6000 km (3729 mi) after the time of sale to the ultimate purchaser, whichever occurs first.
(4) Exhaust systems and exhaust system components that are designed and marketed for use on any Federally regulated off-road motorcycle must be designed and built so that, when installed on any such motorcycle which is in compliance with the requirements of subpart D of this part, and when both the motorcycle and the exhaust system are properly maintained and used, they will not cause that motorcycle to produce noise emissions in excess of the levels specified in paragraph (a)(2) of this section, for an Acoustical Assurance Period of one year or a distance of 3000 km (1865 mi) after the time of sale to the ultimate purchaser, whichever occurs first.
(5) At the time of sale to the ultimate purchaser all products must comply with the standards set forth in paragraphs (a) (1) and (2) of this section.
(b) Measurement procedure. (1)(i) The standards set forth in paragraph (a) of this section refer to the noise emissions as measured in accordance with the measurement methodology specified in appendix I–1 for all motorcycles except those street motorcycles meeting the definition of § 205.151(a)(2)(ii). Exhaust systems which alter a motorcycle's maximum rated RPM shall be tested using the unmodified motorcycle's maximum rated RPM to determine closing RPM or test RPM.
(ii) The standards set forth in paragraph (a) of this section for street motorcycles meeting the definition of § 205.151(a)(2)(ii) (moped-type street motorcycles) refer to noise emissions measured in accordance with the measurement methodology specified in appendix I–2.
(2) Exhaust system components sold as separate products shall be tested as part of a system made up of that part and original equipment components to complete the system.
(3) Exhaust system components sold as separate products which are incompatible with original equipment components necessary to make a complete exhaust system, or which would not meet standards as prescribed in this subpart in such configuration, may be tested with non-original equipment components provided that the provisions of § 205.169(e)(1)(ii)(B) are carried out.