§ 1051.615 What are the special provisions for certifying small recreational engines?
(a) You may certify ATVs with engines that have total displacement of less than 100 cc to the following exhaust emission standards instead of certifying them to the exhaust emission standards of subpart B of this part:
(1) 25.0 g/kW-hr HC + NOX, with an FEL cap of 40.0 g/kW-hr HC + NOX.
(2) 500 g/kW-hr CO.
(b) You may certify off-highway motorcycles with engines that have total displacement of 70 cc or less to the following exhaust emission standards instead of certifying them to the exhaust emission standards of subpart B of this part:
(1) 16.1 g/kW-hr HC + NOX, with an FEL cap of 32.2 g/kW-hr HC + NOX.
(2) 519 g/kW-hr CO.
(c) You may use the averaging, banking, and trading provisions of subpart H of this part to show compliance with this HC + NOX standards (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 meet the applicable emission standards using emission credits, and the vehicles within the family meet the family emission limit). You may not use averaging to meet the CO standards of this section.