This recommended practice establishes equipment and procedures for testing spark arresters used on medium size, single position internal combustion engines, normally used in transportable, stationary, and vehicular applications, such as highway trucks, agricultural tractors, industrial tractors, other mobile equipment, and motorcycles. This recommended practice provides two methods of testing (laboratory testing and engine testing) which may be used to evaluate a spark arrester. It also includes special requirements for screen type devices and an endurance test procedure for screen type spark arresters.