Washington Post: The Environmental Protection Agency yesterday tightened emissions standards for new gasoline-powered lawn mowers, weed trimmers and boat engines, reducing the amount of smog-causing pollution these motors will be allowed to emit. In adopting long-delayed rules that will require small gas engines to have catalytic converters like those that have been installed in cars since 1975, the Bush administration overruled the initial objections of both engine manufacturers and their GOP allies …