Yamaha XF450 5.6L V8 XTO Offshore 25 in.

Convenience and Control

• IN-WATER GEAR LUBE CHANGE SYSTEM: For the ultimate convenience, a technician can drain and replace your outboard’s lower-unit lubricant without having to remove your boat from the water.
• THRUST-ENHANCING REVERSE EXHAUST: For more control at lower speeds and increased precision of our Helm Master® EX boat control system, exhaust is diverted away from the propeller at RPMs below 2,500.
• PUMP STOP POWER TILT LIMIT: The tilt pump shuts off when it reaches maximum tilt setting, rather than continuing to run, saving power and reducing noise at full trim in/out.
• DUAL FLUSH SYSTEM: A unique design offers two methods for flushing the XTO, either through a built-in flushing system hose routed through the rigging tube/grommet or through conventional front-mounted direct-hose hook-up.
• WIDE-SPAN MOUNTING SYSTEM: For minimized vibration and a more compact design, incredibly strong upper motor mounts placed wide on the exterior of the upper mid-section work in conjunction with our Long Span Mounting System.
• PHASE ANGLE CONTROL CHARGING: The XTO’s Phase Angle Control Charging System meets the extreme electrical needs of today’s larger boats. This Innovation Award-winning system produces up to 96 amps of net charging power at idle—from a single outboard—and up to 480 net amps in a quint configuration. That’s up to 65 percent more maximum net charge at idle than previous XTO Offshore models.
• IMPROVED RIGGING TUBE: A redesigned rigging tube provides an extra 3.25 inches of clearance at the motor well when tilted up and is compatible with most flat-transom installations.

Features

• Prop shaft horsepower - 450 hp at 6,000 rpm
• Compression ratio - 12.3:1
• Recommended fuel - Octane 89
• Recommended fuel filtration - Yamaha 10-micron fuel / Water separating filter (external)
• C.A.R.B. rating - 3-Star
• Intake - 32-valve
• Spark plug - ILMAR7E-9 / Iridium
• Ethanol blend limit - 10% maximum
• Degree of tilt - -4° through +73°
• Mounting centers - 28.5 in.
• Compatible control - Digital / Helm Master® EX
• Compatible gauges - CL5 touchscreen display / Digital and analog

Power and Performance

• DIRECT-INJECTION FOUR STROKE: Maximizes power and efficiency by spraying fuel at high pressure directly into the combustion chamber.
• EXCLUSIVE FUEL SYSTEM: A three-stage low-medium-high pressure fuel pump system works, in part, due to two independent, rpm-activated fuel pumps in the Vapor Separator Tank. This unique five-pump system creates an unprecedented fuel injection pressure of up to 2900 PSI to further maximize atomization and efficiency.
• IN-BANK EXHAUST: Intake tracks enter the cylinder head from the outside of the powerhead. This gives exhaust gases room for a direct route to the lower unit and out through the propeller hub, streamlining the powerhead and improving flow.
• XTO (SDS) PROPELLERS: With diameters from 16 to 17 1/8 inches, 15 to 27-inch pitches and increased blade surface, XTO propellers complement the torque potential of our V8 XTO Offshore. They also contribute to greater overall thrust.

Reliability & Durability

• DUAL-CHAMBER OIL PUMP: The XTO's dual chamber oil pump ensures the proper flow and delivery at every engine speed.
• ENDURANCE-DRIVEN CAMSHAFTS: The XTO features dual overhead camshafts that are each connected via a self-tensioning chain immersed in an oil bath and utilize one-sprocket belt engagement. This ensures quiet, precise valve-timing, compact design, low maintenance and long life.
• CARBON-COATED LIFTERS: A special carbon coating on shimless, bucket-style valve lifters increases durability and requires less maintenance.
• PLASMA-FUSED SLEEVELESS CYLINDERS: A micro-textured, plasma-fused design increases fuel economy and is lighter, more compact and 60 percent harder than steel. This allows us to enlarge cylinder bores and increase displacement without increasing the size of the powerhead, all while dramatically reducing friction.
• TWO-STAGE WATER PUMP: This unique design ensures proper cooling water flow at all RPMs and improved temperature control. It features a massive rubber water impeller for high pressure and flow, and a steel impeller that helps provide sufficient water volume, even under the most extreme offshore conditions.

System Integration

• DIGITAL ELECTRIC STEERING: The XTO responds quicker to steering inputs because it contains a digital electric steering motor, which directly receives signals from the electric helm to the integrated steering control unit.