Yamaha recently debuted its most powerful outboard to date, the 5.6L 425 XTO, truly an integrated power system that sports a fresh, new exterior befitting a next-generation engine, and includes a number of technological advances and industry firsts.
Designed to propel today’s large center-consoles and expresses, the new 425 horsepower XTO incorporates a two-stage water pump and dual-chamber oil pump, plus oversized gear case, strengthened camshaft, and more robust bracket and mount for heavy-load operation. Spark plugs are made from iridium to boost throttle response and increase both power and service life. And plasma fusion replaces conventional steel cylinder liners. Significantly lighter and 60 percent harder than steel, the micro-textured surface increases displacement without bulking up the powerhead.
Promising unrivaled power and torque, this newly-developed 4-stroke 5,559cm3 V8 engine features the first fourstroke outboard powerhead to use direct-injection technology, employing five fuel pumps in a three-stage fuel-pressure system that sprays fuel at a high 2,900 psi precisely into each combustion chamber, rather than the intake track, thereby increasing combustion efficiency and providing the ultimate in acceleration and top-speed performance.
Yamaha also packed into the XTO a new integrated electric steering system that eliminates the need for cables or hydraulic lines, provides quicker response to steering inputs, and interfaces with the Helm Master joystick control and CL7 7-inch color touchscreen for easy operation and maximum convenience, as well as an ingenious exhaust-gas relief system that energizes the XTO in reverse, generating up to 300 percent more thrust than Yamaha’s F350. In reverse, below 2,500 rpm, exhaust is diverted away from the prop hub, providing cleaner water for the propeller blades to bite, enhancing astern propulsion and acceleration.
A unique gearcase-lubricant exchange system allows fluid changes while the boat remains in the water, and engineers designed the XTO’s cowling in several parts to make it easier to access specific areas of the powerhead. They also increased the motor’s tilt range 73 degrees, allowing the outboard to rise 5.6 inches higher than the F350, so the motor’s lower unit can be lifted entirely out of the water
The new Yamaha 425 XTO will be available in 25-, 30- and 35-inch shafts, respectively weighing 952, 977, and 999 pounds, in the classic Yamaha gray, white, or unpainted to allow for color customization. Retail pricing will start at $44,000.