The Yamaha XTO Offshore 425hp arrived late in 2018 to relatively little fanfare in Australia, yet this giant four-stroke outboard is one of the most sophisticated, technologically advanced marine engines ever made. We were fortunate enough to trial a pair of these stunning new outboard engines recently, mounted on a Grady-White Express 330.
It’s no secret that outboard-powered fishing boats are reaching new benchmarks, with some 60 footers out there in the marketplace. The problem is that the manufacturers of the largest conventional outboards to date, specifically the Yamaha F350C, Suzuki DF350 and the Merc 350 and 400 supercharged Verados, were not realistic options. Seven Marine dominates the market for super-sized 50- and 60-footers with their GM automotive powerplants that are specially built and marinized to produce either 557 or 627 sea ponies at the propshaft. These engines cost anywhere from $110,000 to $125,000 each, and factory authorized mechanics are few and far between, especially on a busy holiday weekend or 100 miles offshore. Enter Yamaha Marine with their new 425 XTO Offshore “Extreme” four-stroke outboard.

The muscular new shape and dynamic look of the XTO 425hp V8 immediately communicate its incredible industry-first concepts and technologies waiting to be unleashed.

The first direct injection 4-stroke. The first with integral electronic steering, linking seamlessly to Yamaha's Helm Master system. The first to achieve a new level of reverse thrust, torque, and speed. It's a genuine performance revolution for larger boats and an incredible story. Achieve the ultimate. Discover Extreme.

The Yamaha XTO Offshore 425 is a 5559cc V8, twin-cam, 32-valve, four-stroke engine. It was introduced into the Yamaha four-stroke outboard range to compliment the long-running 5.3-litre 350hp model. Both are V8s, but the latest 425hp engine is a completely new design incorporating state-of-the-art features.

Chief among them is the industry first "steer-by-wire" integrated electric power steering system (no pumps or hydraulics), which Yamaha says provides for faster response to steering inputs and better control.

There's also a clever exhaust gas relief system, whereby the exhaust gases are diverted away from the propellers below 2500rpm so the props can bite cleaner water for more thrust in reverse. Yamaha says the new engine delivers 300 percent more thrust in reverse than the smaller Yamaha F350.

Technical Engine Specifications:
  • Engine type: 4-stroke
  • Displacement: 5559 cc
  • No. of cylinders/configuration: 60 Degree V8, 32-valve, DOHC with VCT
  • Bore x stroke: 96 mm x 96 mm
  • Prop shaft output at mid range: 317kW / 6,000 rpm
  • Full throttle operating range: 5,000 - 6,000 rpm
  • Lubrication system: Wet sump
  • Fuel System: Direct Injection
  • Ignition / advance system: TCI
  • Gear ratio: 1.79 (25/14)

Main features of XTO Yamaha 425 outboard for sale
  • Extreme Power – 5.6 L • 32-v • 60º V8 • DOHC • VCT
  • Direct injection 4-stroke;
  • Integrated electronic steering system, perfectly combined with the Yamaha Helm Master system;
  • 300% more thrust from new exhaust system;
  • Reliability – durable, custom-designed crankshaft;
  • Dependability – new robust transmission system;
  • New slim bottom end design with massive gearbox;
  • Dual-chamber oil pump to meet extreme demands;
  • Extremely convenient gear oil change system in water.
  • Recommended boat transom height: X: 640mm
  • Weight with propeller: 442 kg
  • Oil pan capacity: 7.8 litres
  • Control: Drive By Wire Remote Control / Throttle & Gear (DBW RC)
  • Steering: Steer By Wire (SBW)
  • Starting Method: Electric Start (ES)
  • Trim & tilt method: Power trim & tilt (PT&T)
  • Battery Charging:12v - 90A Output
  • Propeller: Included
  • Availability: 10 In Stock
  • Brand: YAMAHA

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