40 CFR 90.2 - Effective dates.
(b) Notwithstanding paragraph (a) of this section, this subpart applies to class V engines, as specified in § 90.116(b)(5), that are preempted from regulation in California by section 209(e)(1)(A) of the Act, effective January 1, 1998.
(c) Notwithstanding paragraphs (a) and (b) of this section, engines used in recreational vehicles with engine rated speed greater than or equal to 5,000 rpm and with no installed speed governor are not subject to the provisions of this part through the 2005 model year. Starting with the 2006 model year, all the requirements of this part apply to engines used in these vehicles if they are not included in the scope of 40 CFR part 1051.
(d) Engines used in emergency and rescue equipment as described in § 90.1(d)(7) are subject to the provisions of this part through December 31, 2009. Starting January 1, 2010 the provisions in 40 CFR 1054.660 apply instead of those in § 90.1(d)(7).
(e) Engines imported for personal use are subject to the provisions of § 90.611 through December 31, 2009. Starting January 1, 2010 the provisions in 40 CFR 1054.630 apply instead of those in § 90.611.