Review: Twin Mercury 350 Verado Outboard Motor

The 350 hp Mercury Verado outboard motor is an extension of the existing 2.6-litre inline six-cylinder Verado series, which is available from 200hp. The new model features revisions to the supercharger, aftercooler, intake and exhaust manifolds, and ECU, allowing for more boost which, when combined with the right fuel, raises power to 350 horses. It shares these upgrades with the epic Mercury 400R outboard that pushes the revisions a step further again.

We had a pair of 25in-legged Mercury 350 engines on the back of the Finnish-designed Axopar 37 Suntop. The GRP hull features twin reliefs, a 20-degree deadrise and axe-bow entry combining for an on-water weight of around 4100kg. The engines were counter-rotating and used 16x19in Enertia propellers.

The Mercury Verado has only one direct competitor – the Yamaha F350 V8 brute of a motor. The Yamaha takes a ‘no replacement for displacement’ approach, packing twice the cubic capacity of the Verado and two more cylinders. You pay for the capacity in weight – the Yamaha is more than 60kg heavier in 25-inch variant. It also features a digital throttle but lacks integrated power steering.

They both run double overhead camshafts with four valves per cylinder, the Mercury 350 Verado using a low-maintenance chain to drive them as opposed to Yamaha’s belt which requires servicing every 1000 hours. The Mercury engine trumps the Yamaha for alternator output, with 70A from the Verado compared to 50 from the F350.

Performance

Crazy fast is probably the best description of how the twins performed on the Axopar 37. Flat out in perfect conditions we saw 48.9kt at 6000rpm from the fresh engines. No doubt when they loosen up a touch, the lucky owner will get closer to the recommended maximum 6400rpm and eclipse 50kt – staggering! Holeshot was excellent, with the hull progressing onto the plane quickly and comfortably.

Economy

Best cruise arrived at 3500rpm, where we saw 24.5kt over ground, the engines sipping only 70L/h combined. That’s an economy rate of 0.35 nautical miles per litre, or a range of 245nm from 700L, more than enough for typical use. Flat out, each engine consumed 120L/h, the same as we’ve seen when reviewing a Yamaha F350 marine engine.

Noise and vibrations

I’ve tested a range of Verados recently, as singles and twins, and each time I’ve come away impressed by the smoothness of the six-cylinder versions. The Mercury 350 outboard didn’t disappoint, especially under load when the rising howl of the exhaust is matched by the whine of the supercharger – addictive and more obvious in the higher-power models.

Controls

I’ve mentioned it in every test where it’s fitted, but again the Mercury SmartCraft Digital Throttle and Shift proved themselves best in class. The twin-mount binnacle is connected by wire rather than cable to the engines and is a pleasure to use. It even features Dock Mode, which reduces sensitivity when docking, making it easier to control the motors.

Steering is power assisted and brilliant. It uses a standalone pump piggy-backed into a hydraulic system to make light work of handling the torque of the engines. Even with twins, on-water handling was light and direct with no hesitation from the system.

VesselView gauges have been out for a couple of years now and still look sharp and are great to use. The touchscreen is bright and easy to navigate; we found setting the fuel burn, revs and speed over ground easy. The engines can backbone into the NMEA2000 system to pass info to your MFD if you don’t want factory gauges.

Servicing and maintenance

The first service is due after 20 hours and then annually or every 100 hours, the norm for modern four-stroke outboards. What stands out for the Mercury outboard against rival Yamaha is the chain-driven camshafts – no costly belt replacement after 1000 hours.

Up top, in the powerhead, roller cam followers that maintain constant valve clearances eliminate periodic adjustments and, from what we know, the materials used in construction are top notch.

The verdict

The Mercury Verado 350 outboard motor is packed with tech, easy to use and delivers good mid-range economy. Flat out it makes the right noises and with its low weight, it is the best in class.

Verado 350: 2598cc inline six, 303kg, three-plus-two-year warranty (recreational)

Yamaha F350 V8: 5330cc V8, 365kg, three-plus-two-year warranty (recreational)

All weights are for 25in legs and correct as of November 3, 2016.

Mercury 350hp Verado sea trials

Twin Mercury 350hp Verado outboards running 16x19 three-blade stainless steel Enertia propellers and fitted to an Axopar 37 Suntop with three people and 550L of fuel on board.

600rpm reaches a speed of 3.2kt with fuel burn of 5.5L/hr and economy of 0.58nm/L for a range of 407nm

3500rpm reaches a cruising speed of 24.5kt with fuel burn of 70L/hr and economy of 0.35nm/L for a range of 245nm

6000rpm (WOT) reaches a maximum speed of 48.9kt with fuel burn of 234L/hr and economy of 0.21nm/L for a range of 146nm

* Sea-trial data supplied by the author. Fuel flow is for both engines combined. Range is calculated leaving 10 per cent fuel in reserve.

Mercury 350 Verado specs

TYPE Inline six-cylinder fuel injected and supercharged petrol outboard

RATED HP 350

DISPLACEMENT 2598cc

WEIGHT 303kg

GEAR RATIO 1.75:1

PROPELLER Stainless steel 16x19 three-blade Enertia