Section 1051.105 - What are the exhaust emission standards for off-highway motorcycles?(a) Apply the exhaust emission standards in this section by model year. Measure emissions with the off-highway motorcycle test procedures in subpart F of this part.(1) Follow Table 1 of this section for exhaust emission standards. You may generate or use emission credits under the averaging, banking, and trading (ABT) program for HC + NOX and CO emissions, as described in subpart H of this part. This requires that you specify a family emission limit for each pollutant you include in the ABT program for each engine family. These family emission limits serve as the emission standards for the engine family with respect to all required testing instead of the standards specified in this section. An engine family meets emission standards even if its family emission limit is higher than the standard, as long as you show that the whole averaging set of applicable engine families meets the applicable emission standards using emission credits, and the vehicles within the family meet the family emission limit. The phase-in values specify the percentage of your U.S.-directed production that must comply with the emission standards for those model years. Calculate this compliance percentage based on a simple count of your U.S.-directed production units within each certified engine family compared with a simple count of your total U.S.-directed production units. Table 1 follows: Table 1 of § 1051.105 -Exhaust Emission Standards for Off-Highway Motorcycles (g/km)
| Phase | Model year | Phase-in (percent) | Emission standards | Maximum allowable family emission limits |
| HC + NOX | CO | HC + NOX | CO |
| Phase 1 | 2006 | 50 | 2.0 | 25 | 20.0 | 50 |
| 2007 and later | 100 | 2.0 | 25 | 20.0 | 50 |
(2) For model years 2007 and later you may choose to certify all of your off-highway motorcycles to an HC + NOX standard of 4.0 g/km and a CO standard of 35 g/km, instead of the standards listed in paragraph (a)(1) of this section. To certify to the standards in this paragraph (a)(2), you must comply with the following provisions:(i) You may not request an exemption for any off-highway motorcycles under § 1051.620 (ii) At least ten percent of your off-highway motorcycles for the model year must have four of the following features: (A) The absence of a headlight or other lights.(B) The absence of a spark arrestor.(C) The absence of manufacturer warranty.(D) Suspension travel greater than 10 inches.(E) Engine displacement greater than 50 cc.(F) The absence of a functional seat.(iii) You may use the averaging and banking provisions of subpart H of this part to show compliance with this HC + NOX standard, but not this CO standard. If you use the averaging or banking provisions to show compliance, your FEL for HC + NOX may not exceed 8.0 g/km for any engine family. You may not use the trading provisions of subpart H of this part.(3) You may certify off-highway motorcycles with engines that have total displacement of 70 cc or less to the exhaust emission standards in § 1051.615 instead of certifying them to the exhaust emission standards of this section. Count all such vehicles in the phase-in (percent) requirements of this section.(b) The exhaust emission standards in this section apply for off-highway motorcycles using the fuel type on which they are designed to operate. You must meet the numerical emission standards for hydrocarbons in this section based on the following types of hydrocarbon emissions for off-highway motorcycles powered by the following fuels: (1) Natural gas-fueled off-highway motorcycles: NMHC emissions.(2) Alcohol-fueled off-highway motorcycles: THCE emissions.(3) Other off-highway motorcycles: THC emissions.(c) Your off-highway motorcycles must meet emission standards over their full useful life. For off-highway motorcycles with engines that have total displacement greater than 70 cc, the minimum useful life is 10,000 kilometers or five years, whichever comes first. For off-highway motorcycles with engines that have total displacement of 70 cc or less, the minimum useful life is 5,000 kilometers or five years, whichever comes first. You must specify a longer useful life for the engine family in terms of kilometers if the average service life of your vehicles is longer than the minimum value, as follows: (1) Except as allowed by paragraph (c)(2) of this section, your useful life (in kilometers) may not be less than either of the following:(i) Your projected operating life from advertisements or other marketing materials for any vehicles in the engine family.(ii) Your basic mechanical warranty for any engines in the engine family.(2) Your useful life may be based on the average service life of vehicles in the engine family if you show that the average service life is less than the useful life required by paragraph (c)(1) of this section, but more than the minimum useful life (10,000 kilometers). In determining the actual average service life of vehicles in an engine family, we will consider all available information and analyses. Survey data is allowed but not required to make this showing. 67 FR 68347 , Nov. 8, 2002, as amended at 70 FR 40487 , July 13, 2005; 73 FR 59246 , Oct. 8, 2008