40 CFR 90.903 - Exclusions, application of section 216 (10) and (11) of the Act.
(a) For the purpose of determining the applicability of section 216(10) of the Act, an internal combustion engine (including the fuel system) that is not used in a motor vehicle is deemed a nonroad engine, if it meets the definition in subpart A of this part. For the purpose of determining the applicability of section 216(11) of the Act, a vehicle powered by a nonroad engine is deemed a nonroad vehicle, if it meets the definition in subpart A of this part.
(b) EPA will maintain a list of models of nonroad engines and models of nonroad vehicles that have been determined to be excluded because they are used solely for competition. This list will be available to the public and may be obtained by writing to the following address: Group Manager, Engine Compliance Programs Group, Engine Programs and Compliance Division (6403J) Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
(c) Upon written request with supporting documentation, EPA will make written determinations as to whether certain engines are or are not nonroad engines. Engines that are determined not to be nonroad engines are excluded from regulations under this part.