The Detroit News reports on a major emissions-limiting ruling by the EPA Thursday that will affect recreational boats and outdoor power equipment with engines smaller than 25 HP. Small engines, such as those found on boats and lawnmowers, are essentially unregulated, making up as much as 25% of current yearly US CO emissions. The new ruling will require a significant reduction in that output, likely necessitating the use of catalytic converters and other pollution control devices. Boat engines will have to meet the new standards starting in 2010, while your lawnmower won't come with an air pump, EGR valve and catalyst until 2011. Hopefully it'll run right on E10 gasoline by then too. Jalopnik Snap Judgment: If you didn't know this was coming, you haven't been paying attention. With the recent focus on global warming and the minor, incremental advances that are left to be made on automobile engines, outdoor power equipment was the next target in sight. So, are we entering the malaise era of the lawnmower? Will our Briggs L-head motors drop from 5 HP to 2.5 HP, saddled with a 5:1 compression ratio and heaps of belt-driven emissions accessories? Probably not. OHV engines have already begun to take over, and they'll likely replace old mower technology, hopefully meeting the new standards with few additions. Boat engines have already gotten pretty high-tech, so it'll likely be even easier for them to pass. The only difference you're likely to see is higher prices. And you're used to that already, right? UPDATED: More information now available at epa.gov. [Detroit News]