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Mercury Racing Offers Taller Gear Ratio For 300R V-8 Outboard Engine

Far from lost—but certainly obscured—in the ongoing discussion in the performance-boating community of what could be next for Mercury Racing’s V-8 outboard engine, the 300R model is now being offered with a 1.60:1 gear ratio in its Sport Master gear case. The naturally aspirated, 4.6-liter outboard, which debuted in mid 2018, originally was released and is still also available with a 1.75:1 gear ratio.


A more aggressive gear ratio is now available to buyers of Mercury Racing’s 300R outboard engines. Photo courtesy Mercury Racing

Mercury Racing applications engineer Nick Nida said the company’s demo MTI 340X catamaran reached a top speed of 115 mph with 1.60:1-ratio 300R outboards on its transom—as opposed to topping out at 113 mph when the 34-footer was powered by 300R outboards with 1.75:1 ratios—during recent tests on Lake X, the company’s test facility in St. Cloud, Fla. Not only was the speed increased without a change in drive height, the boat’s balance was improved, according to Nida.

“The 1.6:1 ratio also will allow for use of more non-cleaver propellers,” he said. “With MAX5 props, for example, we’ve seen 10- to 11-percent slip and a top speed of 110 mph.”

Though they are available for order now, Mercury Racing 300R outboard engines with 1.60:1 gear ratios will begin shipping in May, according to the company’s latest website blog. Conversion kits also will offered for owners of 300R outboards with the 1.75:1 gear reduction.

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“Single and multi-engine applications may realize an improved propeller efficiency with the taller ratio,” wrote Steve Miller, the Fond du Lac, Wis., high-performance marine engine and accessories company’s director of marketing, sales and service in a letter to Mercury Racing boat-builder customers. “Available to order now, the new 1.60:1 Sport Master models join our full suite of 300R high-performance FourStroke offerings.

“All 300Rs come with a 3-year limited factory warranty with up to 5 years of Mercury Product Protection (MPP) available,” he added.

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