Control of Air Pollution; Amendments to Emission Requirements Applicable to New Nonroad Spark Ignition Engines At or Below 19 Kilowatts and New Marine Spark Ignition Engines: Provisions for Replacement Engines and the Use of Two Stroke Engines on Certain Nonhandheld Equipment

This final rule amends the regulations applicable to spark- ignition nonroad engines at or below 19 kilowatts (kW) and spark- ignition marine engines to address situations that have arisen regarding the implementation of regulations applicable to these nonroad engines. No significant air quality impact is expected from these amendments. These amendments will allow engine manufacturers to provide uncertified engines to replace older engines when major engine failures occur and no suitable certified engine is available that will fit in the nonroad equipment or marine outboard or personal watercraft. These amendments will also broaden a provision in the existing regulations which permits the use of two stroke engines to power lawnmowers, subject to a phase-out schedule described in the regulations. The amendments will extend this provision to other types of nonhandheld equipment subject to appropriate constraints.