ENGINE REVIEW - MERCURY RACING ROS FOUR STROKE
Following the release of the Mercury Verado 400R outboard, Mercury has announced another race-ready marine engine, this one aimed at offshore powerboat racers.
The new Mercury Racing ROS FourStroke racing outboard was developed in conjunction with the World Professional Powerboating Association (WPPA) and will replace the existing fleet of Mercury Racing TwoStroke 2.5lt EFI, used in this tournament and elsewhere.
The Mercury ROS does not appear to be a standard Verado engine, what with its midsection replaced with a billet aluminium housing which lowers the engine’s centre of gravity.
Used in combination with solid engine mounts, we’re told this lower centre of gravity assists handling at competition speeds, particularly when powering high-performance boats in and out of corners.
The Mercury Racing ROS FourStroke racing outboard motor uses a remote dry sump system, which holds eight litres of Four Stroke Oil, the same semi-synthetic 25W-50 oil used to lubricate Mercury high-output sterndrives.
Mercury Racing GM Erik Christiansen said the venerable Mercury 2.5lt EFI TwoStroke had been a mainstay for many years and was a solid product, “… but the Mercury ROS builds on that foundation while using the FourStroke technology to meet market demands.”
The new outboards are joined by five-and six-blade CNC Cleaver propellers, featuring an over-the-hub exhaust design, developed specifically for surface piercing applications such as offshore powerboat racing.