Seven Marine 527 Outboard Review

Maker of World's Largest Outboard Debuts New Model

Seven Marine 527 Outboard Review
A less complex cowl covers the supercharged 6.2-liter V-8 powerhead of this new outboard from Seven Marine.Courtesy Seven Marine

Seven Marine expanded its mega-­power outboard line to three models a little more than a year after its acquisition by Volvo Penta. The new Seven 527's reduced price is intended to make Seven models accessible to more buyers, although ­Volvo Penta policy, unlike that of other engine-makers, dictates that Seven no longer publishes retail pricing (in 2016, we reported a Seven 557 base price of about $80,000 plus rigging). Behind the scenes, the affiliation has reduced the cost of some basic components and opened the door for Seven at new suppliers. Volvo also offers more-advanced testing and validation processes for Seven, according to Rick Davis, Seven Marine president and CEO.

The company says a redesigned cowl significantly reduces the cost of the 527 versus other Seven motors. The cowl features louvers in its top in place of the large scoop-shaped vent seen on the other Seven cowls. The 527 cowl does not accommodate the LED lighting options or the unlimited paint-and-finish options available for other Seven models. A new 1.91-to-1 gear ratio allows the 527 to produce outstanding torque.

Each of the Seven Marine models is powered by a ­6.2-liter GM LSA Gen IV V-8 engine with a closed cooling system. Power output is determined by supercharger boost pressure and electronic engine tuning. Many of the features ­originally developed for the Seven 627 model, including high-­performance cylinder heads and camshaft, and durable ­Inconel exhaust valves, have trickled down the model line in what has become a standardized engine package. The engine is mated to a ZF transmission with wet-disc clutch shifting, and to a twin-pinion gear case. All models feature integrated power steering and can be rigged with joystick controls.

The Seven 577s model is ­full-featured, with SpectraLight LED lighting (rear of cowl only) and limited color options. The Seven 627sv features ­SpectraBlade LED lighting (on the rear, top and sides) and can be ordered with unlimited custom paint color options. Note that each of these engines has a peak rpm of 6,000; Seven is not achieving more power by raising engine speed. There are three gear-case options: A single-­prop case is rated for up to 80 mph; the CR gear case comes with four- or five-blade contra-­rotating props and a massive blade area for lifting heavy boats on plane; and the bullet-­nose GT gear case is good for boat speeds in excess of 85 mph.