News & Events

Yamaha has unveiled its new 5.6L V-8 outboard, the 425 XTO, designed to move big center console and express boats. The company says its engineers redesigned this outboard from the props up and added all kinds of new technologies.

We’d say it’s a game changer.  Here’s why:

• This is the first four-stroke powerhead in the outboard industry to use direct injection. Fuel is sprayed at high pressure directly into the combustion chamber rather than the intake track. This improves atomization and increases the effectiveness of the fuel burn.

• The direct-injection system features five fuel pumps and injection pressure up to 2,900 psi. The three-stage fuel-pressure system is, in part, composed of two independent fuel pumps within the Vapor Separator Tank (VST) that activate at specific, individual rpm. This ensures proper fuel flow and delivery, even at very high engine rpm.

• This engine has the highest compression ratio in an outboard at 12.2-to-1. That means more bang from every spark as well as better efficiency and power (enabled in part by the piston-cooling effects of direct injection).

• The XTO comes with integrated electric steering. So, there are no hydraulic lines or linkages. Yamaha says this system responds more quickly than conventional systems to steering inputs.

• XTO OS propellers range in diameter from 16 to 17 1/8 inches, offering increased blade surface area for moving big boats and yachts.

• In addition to an oversized gear case, hardened gears, and a robust, offshore bracket and motor mounts, the V8 XTO Offshore outboard also has a two-stage water pump and dual-chamber oil pump, each designed to respond to heavy loads.

• Spark plugs are made from the rare element iridium, to improve throttle response and economy, increase service life and improve power.

• The XTO comes with quad thermostats, two per cylinder bank. One pair helps regulate engine temperature; the other helps regulate oil temperature.

• Yamaha credits its new exhaust-gas relief system for energizing the XTO in reverse, generating up to 300 percent more thrust than the company’s F350. Shift into reverse, throttle back and the boat accelerates quickly as water crests the top of the transom bulkhead. Exhaust is diverted away from the XTO’s big props below 2,500 rpm, meaning the blades bite clean water.

• Yamaha designed the new cowling for the outboard in several parts to make it easier to access to specific areas of the powerhead. A unique gearcase-lubricant exchange system allows fluid changes while the boat remains in the water.

• Engineers also increased the engine tilt range up to 73 degrees. The outboard extends 5.6 inches higher out of the water than the F350; the entire motor and lower unit can be raised completely out of the water.

You get the idea. This is one big, powerful, go-hard outboard engine designed for big boats and high seas, built with all the modern, high-tech bells and whistles. In other words, Yamaha has set a new standard. The game has been changed!

Stop by OHM and take a look at this futuristic outboard today.

Yamaha’s 5.6L V-8 425 XTO brings to market several four-stroke firsts — from direct injection to electric power steering. Yamaha says its engineers rethought the outboard from the prop up to propel today’s large center-consoles and expresses. Highlights include the highest compression ratio in an outboard at 12.2-to-1, a new oversize prop, an oversize gear case, iridium spark plugs, quad thermostats, and a new exhaust-gas relief system that energizes the XTO in reverse, generating up to 300 percent more thrust than the company’s F350. Available in gray, white or unpainted (for color customization), and in 25-, 30- and 35-inch shafts (weighing 952 to 999 pounds), the XTO starts at $44,000.

Yamaha’s all-new 5.6L V8 425 XTO, the most powerful outboard from this company since the F350 debuted in 2007, brings to market several firsts — from direct injection to electric power steering. Yamaha says its engineers rethought the outboard engine from the prop up to propel today’s large center-consoles and expresses.

“This is an integrated outboard system, designed to push the heaviest offshore boats and yachts,” says Ben Speciale, Yamaha Marine Group President. “The new Yamaha V8 XTO Offshore has 5.6 liters’ tremendous thrust and 425 horsepower.”

The 425 hp XTO is available for single, dual, triple and quad configurations.

Courtesy of Yamaha

Here are some of the highlights Yamaha related to boating media about the new XTO during its debut in late May:

• First fourstroke powerhead in the outboard industry to use direct injection. Fuel is sprayed at high pressure directly into the combustion chamber rather than the intake track. This improves atomization and increases the effectiveness of the fuel burn.

• The direct-injection system features five fuel pumps and injection pressure up to 2,900 psi. The three-stage fuel-pressure system is, in part, composed of two independent fuel pumps within the Vapor Separator Tank (VST) that activate at specific, individual rpm. This ensures proper fuel flow and delivery, even at very high engine rpm.

• Highest compression ratio in an outboard at 12.2-to-1. That means more bang from every spark as well as better efficiency and power (enabled in part by the piston-cooling effects of direct injection).

The V8 425 comes in white, gray or unpainted. The electric steering unit resides in the cylinder just below the front of the powerhead.

Courtesy of Yamaha

• The XTO comes with integrated electric steering. So, there are no hydraulic lines or linkages. Yamaha says this system responds more quickly than conventional systems to steering inputs.

• XTO OS propellers range in diameter from 16 to 17 1/8 inches, offering increased blade surface area for moving big boats and yachts.

• In addition to an oversized gear case, hardened gears, and a robust, offshore bracket and motor mounts, the V8 XTO Offshore outboard also has a two-stage water pump and dual-chamber oil pump, each designed to respond to heavy loads.

• Spark plugs are made from the rare element iridium, to improve throttle response and economy, increase service life and improve power.

• The XTO comes with quad thermostats, two per cylinder bank. One pair helps regulate engine temperature; the other helps regulate oil temperature.

The 425’s cowling was designed in parts to facilitate maintenance.

Courtesy of Yamaha

Yamaha credits its new exhaust-gas relief system for energizing the XTO in reverse, generating up to 300 percent more thrust than the company’s F350. Shift into reverse, throttle back and the boat accelerates quickly as water crests the top of the transom bulkhead. Exhaust is diverted away from the XTO’s big props below 2,500 rpm, meaning the blades bite clean water.

Yamaha designed the new cowling for the outboard in several parts to make it easier to access to specific areas of the powerhead. A unique gearcase-lubricant exchange system allows fluid changes while the boat remains in the water.

Engineers also increased the engine tilt range up to 73 degrees. The outboard extends 5.6 inches higher out of the water than the F350; the entire motor and lower unit can be raised completely out of the water.

Yamaha’s new V8 was designed from the prop up to push big center-console and express boats.

Courtesy of Yamaha

The XTO will be available in gray, white, or unpainted (for color customization by a boat builder), and in 25-, 30- and 35-inch shafts. Retail pricing will start at $44,000. Yamaha also upgraded its Helm Master features and its CL7 display for the XTO.

SPECIFICATIONS:

ENGINE

Type…………………………………………………… 4-Stroke, DOHC V8 – 32 valves

Displacement……………………………………….. 5559 cm3

Bore x Stroke……………………………………….. 96.0 x 96.0 mm

Full Throttle RPM Range………………………… 5000 – 6000

Variable Trolling RPM Range……………………. 600 – 1000 RPM

HP Rating at Propshaft………………. 425hp @ 5500 RPM

Compression Ratio………………………………… 12.2:1

Fuel Induction/Scavenging………………………DOHC, DI, 4 Valves per Cylinder

Alternator Output………………………………….. 90 Amps Gross, Max

Starting Method……………………………………. Electric w/ PTT

Ignition……………………………………………….. TCI Microcomputer

Lubrication…………………………………………..Wet Sump

Degree of Trim……………………………………… -4° through +16°

Degree of Tilt……………………………………….. -4° through +73°

Exhaust………………………………………………. Through Propeller (Except in Reverse Under 2500 RPM)

Cooling………………………………………………..Water, Thermostatic Control

Steering………………………………………………. Integrated, Electric Actuation

DRIVE

Gear Ratio……………………………………………. (25/14) 1.79

Control Method…………………………………….. Digital Electronic Control