More boat owners want big outboards for their cruising boats, and Yamaha has delivered, just unveiling a new 425-hp V-8, its most powerful ever. Yamaha says this new engine features the first application of direct injection technology in a four-stroke outboard; this sprays fuel at high pressure directly into each combustion chamber, rather than the intake track, providing more efficiency, power and torque with faster acceleration and a higher top speed. The new outboard also is the first time Yamaha has used sleeveless cylinders, formed through plasma fusion technology, and iridium spark plugs for reliability and durability. The company says…