This rulemaking amends the regulations applicable to new gasoline spark-ignition marine engines to address an oversight regarding the production line testing program in the final regulations published on October 4, 1996, (61 FR 52087). No air quality impact is expected from these amendments. This amendment will allow spark- ignition marine engine manufacturers to delay the implementation of the production line testing program until MY 1999 for outboard engines and until MY 2000 for personal watercraft engines.