Outboard Engines

Everything You Wanted to Know About Mercury’s 600-HP Outboard But Couldn’t Afford to Ask

By Martin Frobisher

Mercury 600-hp outboard 3,600-hp, 288 valves, 72 cylinders and 6 engines for one boat.

3,600-hp, 288 valves, 72 cylinders and 6 engines for one boat.

The Mercury 600-horsepower outboard engine introduced in February of 2021 represents a significant leap forward in marine propulsion technology, combining sheer power with innovative engineering including a two-speed automatic transmission and standard counter-rotating propellers.

Uniquely, the lower unit steers, while the powerhead remains in fixed position.

Transmission shifting is managed by an engine controller, based on power demand. In a multi-engine setup, each motor shifts individually per Mercury. There’s no manual shifting from low to high gear—the engine does it automatically based on torque demands as signaled from the throttle and load.

If you hammer the throttle while off plane, the transmission automatically shifts to low to supply the needed torque, then downshifts smoothly as the boat gets on full plane.

Mercury’s 600-hp V12 outboard engine

Mercury’s 600-hp V12 outboard has changed the game in powering larger yachts and performance boats that once were considered for inboard power only.

A Big Engine with a Big Price

The Mercury 600-horsepower outboard has a 7.6-liter (463.8 CID) fuel-injected, naturally-aspirated V12 powerhead. This engine delivers enough horsepower to drive very large, heavy boats with ease. Boats to over 50’ long are now being powered by multiple 600’s. 

It’s a monster engine—weight is 1,260 lbs (571.5 kg) in standard long shaft--and it has lead to rapid evolution of larger boats designed for multiple high-output motors. 

The price is as large as the outboard, starting at some $77,000 each. With joystick and other options, the price for each motor approaches $100,000

The Mercury V12 stands on end

The Mercury V12 stands on end to create a smaller powerhead, allowing multiple motors to sit side-by-side on many transoms.

The V12, quad-cam configuration not only provides exceptional power but also smoother running compared to V6 and V8 engines. It’s also exceptionally quiet considering the impressive power output.

The Mercury 600 is equipped with the latest generation of Mercury’s Digital Throttle and Shift (DTS) system, which allows for effortless precise control over the engine’s performance. This system enhances the driving experience by providing smooth and responsive throttle and shift operations, making it easier for boaters to handle vessels easily, particularly in multi-engine setups.

Rigging at the transom is also much cleaner due to the electrical steering and shifting system.

The Mercury 600 Propeller System

The forward propeller on the lower unit is larger than the aft propeller.

Front prop diameter ranges from 18.25 inches for the 23-pitch prop to 16.5 inches for the 37-pitch prop, while diameter of the rear prop ranges from 16.75 to 15.0 inches. 

There are nine different propeller combinations to suit a wide variety of boat weights and boating applications. The prop sets are about $3,300 for the pair.

Mercury 600 lower unit

The lower unit steers independently of the powerhead, and counter-rotating props provide a strong grip on the water.

The Steerable Lower Unit

The lower unit steers digitally, so the rigging to the motor from the helm is minimal. At idle speed the lower unit can turn 45 degrees in each direction, giving a huge advantage in docking in tight locations or in holding position via a GPS “anchor”. 

At planing speed, the lower unit is limited to turns of about 30 degrees in either direction.

Multiple Verado 600’s can push boats to 50’ and larger

Multiple Verado 600’s can push boats to 50’ and larger like this Formula at impressive speeds and still maintain reasonable fuel economy.

Another notable feature is the advanced onboard diagnostics system, which provides real-time information about the engine’s performance and condition. This system alerts the operator to any potential issues before they become serious problems, allowing for timely maintenance and minimizing the risk of unexpected failures.

Shifting Mechanism:

The shifting mechanism of the Mercury 600 is a significant advancement in marine propulsion systems. It employs Mercury’s innovative Electro-Mechanical Shift (EMS) system, which represents a major departure from traditional mechanical or hydraulic shift systems. The EMS system uses electronic controls to manage gear changes with exceptional precision and speed. This system is designed to deliver seamless and smooth shifting between forward, neutral, and reverse gears.

Mercury 600 shifting transmission

The shifting transmission sits in the mid-section of the Mercury 600. It shifts automatically as needed based on load, with no direct input from the helm.

Alternator Output:

Another critical aspect of the Mercury 600 is its alternator, which plays a crucial role in powering onboard electronics and maintaining the battery charge. The outboard is equipped with a high-output alternator capable of delivering up to 150 amps of electrical power. 

This substantial output is designed to meet the demands of modern marine electronics, including advanced navigation systems, entertainment devices, and auxiliary equipment. The motor also senses the need for added charging when there’s a lot of electrical draw and increases idle speed to compensate. 

Engine Servicing

Oil change increments are 200 hours rather than the usual 100, and the top cowl service hood allows for easy access to oil dip stick, fuel filter, oil filter, etc. In fact, the full cowl doesn’t need to come off for regular maintenance until hitting the 1000 hour or five year service mark, per the company.

Overall, the Mercury 600 is a major step forward in propulsion of larger boats, and since its introduction three years ago has already had a profound effect on boat design and engineering, with many manufacturers now producing larger yachts and performance boats designed specifically for outboard power.