40 CFR 91.1 - Applicability.
(a) This part and all its subparts apply to marine spark-ignition engines used to propel marine vessels as defined in the General Provisions of the United States Code, 1 U.S.C.3 (1992), unless otherwise indicated.
(b) Sterndrive and inboard engines are exempt from this part.
(d) This part does not apply to engines that are subject to emission standards under 40 CFR part 1045. See 40 CFR 1045.1 to determine when that part 1045 applies. Note that certain requirements and prohibitions apply to engines built on or after January 1, 2010 if they are installed in equipment that will be used solely for competition, as described in 40 CFR 1045.1 and 40 CFR 1068.1; those provisions apply instead of the provisions of this part 91.