Section 1051.20 - May I certify a recreational engine instead of the vehicle?(a) You may certify engines sold separately from vehicles in either of two cases: (1) If you manufacture recreational engines but not recreational vehicles, you may ask to certify the engine alone. In your request, explain why you cannot certify the entire vehicle.(2) If you manufacture complete recreational vehicles containing engines you also sell separately, you may ask to certify all these engines in a single engine family or in separate engine families.(b) If you certify an engine under this section, you must use the test procedures in subpart F of this part. If the test procedures require vehicle testing, use good engineering judgment to install the engine in an appropriate vehicle for measuring emissions.(c) If we allow you to certify recreational engines, the vehicles must meet the applicable emission standards (including evaporative emission standards) with the engines installed in the appropriate vehicles. You must prepare installation instructions as described in § 1051.130 and use good engineering judgment so that the engines will meet emission standards after proper installation in the vehicle.(d) Identify and label engines you produce under this section consistent with the requirements of § 1051.135 . On the emission control information label, identify the manufacturing date of the engine rather than the vehicle.(e) You may not use the provisions of this section to circumvent or reduce the stringency of this part's standards or other requirements.(f) If you certify under paragraph (a)(1) of this section, you may ask us to allow you to perform production-line testing on the engine. If you certify under paragraph (a)(2) of this section, use good engineering judgment to ensure that these engines are produced in the same manner as the engines you produce for your vehicles, so that your production-line testing results under subpart D of this part would apply to them.(g) Apply the provisions of 40 CFR part 1068 for engines certified under this section as if they were subject to engine-based standards. For example, you may rely on the provisions of 40 CFR 1068.261 to have vehicle manufacturers install catalysts that you describe in your application for certification. 70 FR 40489 , July 13, 2005, as amended at 75 FR 23023 , Apr. 30, 2010