All new 250R and 300R outboards
by Mercury Marine 27 Jun 2018 12:04 BST

Mercury Racing all-new 300R © Mercury Racing
Mercury Racing is excited to debut its all-new 300R and 250R outboards.
Designed, developed and manufactured in-house, the naturally aspirated V-8 4.6L FourStroke engines share Mercury Racing's venerable Quad Cam Four Valve (QC4) sterndrive DNA – complete with aluminum four-valve cylinder heads and dual overhead camshaft (DOHC) valve train.
The four valve heads and DOHC valve train is integrated with Mercury's proprietary V-8 cylinder block, packed with high performance hardware.
The new platform replaces the two-stroke V-6 250XS and 300XS models.
The stout V-8 powerhead provides an astounding 44% in increased displacement compared to the legacy two-strokes.
That, combined with four valves per cylinder and the DOHC valve train, enables the new four-strokes to generate unprecedented torque and unmatched acceleration from the lower end of the power band up to maximum engine speed, all on regular unleaded (91 RON) fuel.
Impressively, the new engines are comparable in weight to the older two-stroke cousins, with the weight savings due to the state-of-the-art powerhead components including composite intake runners.
The 250R pumps out 250 prop shaft horsepower and much higher torque than the 250XS it replaces. The efficient and durable Sport Master gearcase, in the correct application, will enhance boat handling, top speed and efficiency.
The 300R is the most powerful engine in its class. The 300R powerhead features Mercury Racing-specified intake cam shafts, valves and an exclusive short runner intake manifold.
An integrated oil cooler keeps oil temps down throughout the Mercury Racing exclusive 5800-6400 rpm operating range. A multitude of models with two midsections and three gearcase options in varying shaft lengths are available to revolutionise nearly any boating experience.
Both new engines accept either traditional throttle and shift cables or DTS (Digital Throttle & Shift).
Throttle and shift actuation, handled electronically on the engine for both traditional and DTS rigging, replaces the lag and hesitation of mechanical throttle and shift cables with digital precision, resulting in smooth shifting and instant throttle response.
The availability of either rigging system enhances the repower versatility of the engine.
Both models are backed by a 3-year limited warranty for recreational use only.