(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.
(c) Existing technology OB/PWC are exempt from Sec. 91.112 and subparts D, E, F, G, I (Secs. 91.803 through 91.805), J, M and N through model year 2003.
(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. [61 FR 52102, Oct. 4, 1996, as amended at 73 FR 59183, Oct. 8, 2008]