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Mercury Marine Introduces V-8s Across Outboard Engine Lines

In terms of sweeping changes to a marine engine program, they don’t get any bigger than Mercury Marine’s move to a 4.6-liter V-8 platform for much of its outboard line. While there are six-cylinder outboards—most notably the Verado 350 and Mercury Racing Verado 400R for the high-performance marine market—still remaining in the Fond du Lac, Wis., company’s product portfolio, the future is decidedly V-8.


Mercury Racing’s new V-8 300R and 250R outboard engines “share DNA” with the company’s Quad Cam Four Valve stern-drive engine platform.

As for the direct-injection two-stroke OptiMax engine series, it has been discontinued. With the exception of one commercial-use model, Mercury Marine now is completely out of the two-stroke outboard engine market.

Members of the marine media learned about the changes—and experienced the new outboard products firsthand—during a recent clandestine event at Lake X, Mercury Marine’s recently reopened private testing and product development facility near Orlando, Fla.

All based on the same 4.6-liter V-8 platform, the new outboards include the Mercury Racing 250R and 300R, which are both naturally aspirated as opposed to their remaining supercharged Verado 400R and (Mercury Marine) Verado 350 siblings.

mercuryracing300r 01

Click image to enlarge.

“Designed, developed and manufactured in-house, the naturally aspirated, 4.6L V-8 four-stroke engines share Mercury Racing’s venerable Quad Cam Four Valve (QC4v) stern-drive DNA—complete with aluminum four-valve cylinder heads and dual overhead camshaft (DOHC) valve train,” a Mercury Racing press release stated. “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 250R and 300R come with Mercury’s conventional midsection rather than advanced midsection of its Verado 350 and 400R siblings—hence the reason for dropping “Verado” from the product names. Both engines come with limited three-year warranties.

Click this link to watch a video of the new outboards in action.

A heavier-duty version of the 300-hp Mercury Racing V-8, the 300HD model features an extra-stout forged clamp bracket assembly with single-ram trim cylinder. (The trim pump itself is mounted remotely in the boat.)

“The 400ROS outboard uses the same system,” said Rick Mackie, Mercury Racing’s senior marketing specialist. “The heavy-duty clamp bracket assembly is offered on selected Sport Master gearcase models and all 5.44-inch HD gearcase models designed for offshore applications.”

mercuryrracing250300rspecs 02

For complete specifications of Mercury 250R and 300R, click the image above.

“With all these new releases, we’ve been working to clean up nomenclature across the outboard line,” said Stuart Halley, Mercury Racing’s new general manager. (To read his interview, which went live concurrently with this story, click here.)

While a knowledgeable Mercury Marine official said that the naturally aspirated V-8 platform is easily capable of producing power well beyond its current maximum output of 300 hp, he also said buyers eager for something from Mercury more potent than the Mercury Racing Verado 400R outboard will have to wait until 400R sales peak and cool off. And those sales are showing no signs of doing either anytime soon.

mercuryracing250 01

Click image to enlarge.

For the single-engine sport catamaran and high-performance bass boat markets, Mercury Marine also introduced the four-stroke 4.6-liter V-8 Pro XS 300 and Pro XS 250 outboards. On the less-high-performance-oriented value side of the market, the company also introduced a same-powerhead-based, naturally aspirated Verado 300 outboard and a 200-hp Four-Stroke series model.

Related story:
Meet Stuart Halley—Mercury Racing’s New General Manager
Gallery Of The Week—Lake X, Then And Now