Minimal weight achieved with Mercury Racing 450R

The new Mercury Racing 450R outboard has been designed in-house
The new Mercury Racing 450R outboard has been designed in-house
The 450R has a 4.6-litre V8 four-stroke powerhead
The 450R has a 4.6-litre V8 four-stroke powerhead
Industry Database

The new Mercury Racing 450R outboard has been designed for high-performance applications.

The engine has a 4.6-litre V8 four-stroke powerhead boosted by a Mercury Racing supercharger to produce 450hp and 40% higher torque than the 400R.

“The launch of the new Mercury Racing 450R outboard has been long anticipated,” commented Ben Allen, general manager for the Marine Leisure Division of UK distributor E P Barrus.

“This sets us way ahead of our competitors with not only the power and weight, but the technologies to back it up. We’re very excited to introduce this to our customers, boat builders and authorised dealers alike, and look forward to the opportunities that it brings.”

The outboard has been designed and developed in-house and is based on the same 4.6-litre V8 powerhead used for the normally aspirated Mercury Racing 300R outboard models.


To maintain peak performance, a boost bypass valve automatically adjusts maximum boost pressure in response to changing ambient conditions.

To manage engine heat, the Mercury Racing 450R is fitted with a high-capacity oil cooler and a poppet valve in the midsection to provide a higher volume of cooling-water flow on-demand.

The electronics and engine components are all designed and positioned to create the tightest package possible while maintaining good service access.

Like all Mercury Racing outboards, the 450R accommodates 26in centre-to-centre mounting on multi-engine transoms.

Minimal weight

The weight and design of each component has been considered to achieve maximum power with minimal weight.

The operating range extends from 5800-6400rpm, with a full collection of Mercury Racing propellers available to optimise acceleration, efficiency and top speed.

The Mercury Racing Advanced MidSection (AMS) features heavy-duty stainless-steel guide plates and stiffened engine mounts to stabilise the outboard and enhance high-speed handling.

The AMS also isolates the powerhead from the transom for smooth and quiet running. Standard electro-hydraulic power steering offers confident and precise control at all speeds.

The outboard has a 115-amp alternator for extreme audio systems and power-hungry electronics.

Alternator output

When the idle charge battery-management system senses low battery voltage, it automatically increases engine idle rpm to boost alternator output until batteries are charged to the proper level.

The Sport Master gearcase, designed for boats capable of speeds in excess of 85mph, features low water pick-ups and for the 450R application, a new, one-piece, 1.25in diameter stainless-steel propshaft.

Mercury transient spark technology applies pre-programmed timing advance to optimise torque output for stronger hole-shot performance and adaptive speed control with a custom Mercury Racing calibration automatically holds engine rpm regardless of load or condition changes.

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