Yamaha 425HP DEC | LXF425USB

The Yamaha LXF425USB is the 425 hp flagship of the XTO Offshore line, an eight-cylinder four-stroke on a 30-inch shaft with integrated electric steering, digital throttle, and electric start. At 977 pounds and 5,559cc of displacement, this is built for the largest offshore boats running a single big engine rather than twins.

Engineering highlights

Iridium spark plugs and quad thermostats are built in to keep combustion and temperature consistent across all eight cylinders, and direct fuel injection replaces the electronic injection used on Yamaha's smaller four-stroke outboards in this lineup. A counter-rotation lower unit is also offered for boats that pair two of these engines together.

Fitment and weight

Match the 30-inch shaft to your transom, and confirm your rigging supports integrated electric steering and digital throttle rather than a mechanical cable. At 977 pounds, verify your transom's rated capacity carefully before ordering; a propeller is not included.

Leave the rigging to a specialist

A motor and electric steering system this size is not a weekend bolt-on project for most owners; having a qualified rigger handle the mounting, wiring and steering integration up front avoids far costlier fixes down the line.

What's included

Power trim and tilt, the electric steering system itself, electric start, a safety lanyard, and a dual flush system all come standard, and this unit is sold new.

Common questions

What's the displacement? 5,559cc across eight cylinders.