MerCruiser Dependability

Published in the August 2012 Issue August 2012 Ask The Expert

Innovation is a large part of what makes Mercury Marine unique. It was the principle behind the beginnings of the company in 1939 when founder and engineer E. Carl Kiekhaefer repaired, improved and sold 300 defective outboard engines. Having never given up that spirit of innovation, Mercury Marine is now considered one of the world's top manufacturers of recreational marine engines.

Mercury's MerCruiser line of sterndrive engines definitely lives up to that reputation. Here is a closer look at what this engine manufacturer has to offer and some of the stand-out features that make its engines so great.


Sky's The Limit

Mercury Marine offers several engine options for pontoons and deck boats. The wide selection allows you to choose one that fits your needs and your budget. Options range from the dependable four-cylinder 3.0L MPI ECT to the monster 425hp V8 8.0L H.O. DTS ECT.

The most commonly installed engine for deck boats in the MerCruiser line is the 4.3L MPC ECT. Actually the V6 engine is a great option for both deck boats as well as pontoons because of the size. The design of the engine is a proven workhorse and is built to last. It also features Engine Guardian that ensures that engine vitals are kept within a safe level.

Several years ago, the only tool you had for diagnosing issues with your engine was an often-cryptic mix of lights and buzzers. Engine Guardian is one of several innovations from Mercury Marine that work to improve the monitoring of vitals of the engine.

The system categorizes issues two ways: critical and not critical faults. Let's say you're cruising along and a plastic bag gets picked up by the lower intake. This would classify as a critical fault because you now run the risk of overheating your engine due to the lack of being able to water cool your engine.

Engine Guardian is designed so the operator of the boat can actually interpret the error that is being given. In this case, the system would register a critical low-pressure fault and, for this specific problem, give one continuous beep.

If you have Mercury's SmartCraft gauge technology inside the boat, Engine Guardian features what is called Descriptive Fault text. In the example being used here, a text would display a messaging alerting the operator there is a critical fault of low water pressure and would recommend returning to port.


Safe Mode

Engine Guardian's engine-saving features don't stop there either. If in this case you have received the alert about low water pressure and you have not let off the throttle, the system will, after a short amount of time, proactively bring the throttle down and limit it to a safe level to help save the engine.

The system will also monitor non-critical faults and recommend you take it to a dealer at your earliest convenience.

"We want to keep our customers out on the water as much as possible," says Steve Miller, senior category manager at Mercury Marine. "Not everything that comes up means that you have to return to port."

Engine Guarding is not the only innovation on the MerCruiser line of engines that gives you control over your boat. SmartCraft Digital Throttle & Shift (DTS) is a popular feature as well.


Going Digital

DTS replaces mechanical throttle and shift cables and ushers into the digital era. The system uses a flexible data cable that goes from a unit by the driver to the engine to electronically control those same functions.

Miller notes that the system works really well with pontoon boats.

"When you are rigging a pontoon you've got some challenges with how you're routing mechanical cables," says Miller. "The more you bend and twist a cable, the harder it gets to shift a boat."

Because DTS uses a data cable, you can route it the way that is the most convenient. Whichever way the cable goes, you can be ensured of effortless throttle and shift control. The system will also monitor vitals such as fuel use, rpms, engine trim and efficiency, and displays them on a digital LCD screen.

The system also features an ECO-Screen that helps deliver the best possible fuel economy from your boat. It monitors engine rpm, engine trim, speed and fuel consumption together to help guide you to the settings that will deliver the best fuel efficiency. The display will glow green when you reach maximum fuel economy.

A features that MerCruiser is particularly excited about is the docking mode. Once you push "Docking Mode" on the screen, the DTS system will automatically reduce throttle sensitivity by about 50 percent. So, for example, if you were in that mode and you had your throttle lever at full, it would end up being only about half the power.

"It's helpful for new boaters because there is a tendency when you are coming into dock to sometimes over-compensate with the lever and there is somewhat of a panic factor," says Miller. "This takes some of the stress out of that situation."

This system is only available on select outboard sterndrive engines, but is definitely worth considering for future purchases.



Another innovation from Mercury Marine proves that you can have a lot of fun on a boat but also be conscious of the environment with Emissions Control Technology (ECT). The system was designed so that you can get the same performance as a non-EFT engine, while improving cruising fuel economy as well.

The system uses a catalytic converter in each of the exhaust banks along with other sensors. The purpose of the converter is to take the harmful pollutants that normally come from the exhaust of an engine and convert them into less-harmful emissions before they leave the exhaust pipe.

The system complies with the California Air Resources Board (CARB) and the Environmental Protection Agency (EPA) emissions requirements. As an added benefit, there are also increases in noise reduction, which is sure to keep everyone happy on the boat.



One of the more exclusive innovations that Mercury Marine offers is SeaCore corrosion protection. While some competitors resort to enclosing the drive components in a plastic shell, SeaCore goes beyond and above that to deliver industry-leading protection from damage caused by saltwater.

Saltwater can be devastating for an engine, and it's not possible to move an inboard or sterndrive engine out of a boat like you can an outboard.

"When you immerse engine components in saltwater you're in a situation that is highly conducive to corrosion unless your take some measure to treat the product and coat it," says Miller.

Available as an option on most of Mercury's sterndrive engines, SeaCore takes the drive through a hard anodization process. The result is metal perfect for the seas.

"It basically changes the surface and composition of the metal a little bit to the point that it becomes so hard and non-porous that corrosion just can't get into the pore of the metal," says Miller.

The engine also features a closed cooling system that uses five-year coolant that seals out saltwater. Stainless steel is used extensively throughout the system, including quality-grade 316 components for all underwater drive fasteners, steering shaft and motor mounts. The MercFusion paint system protects the engine by creating a tough and durable barrier from corrosion.

Mercury backs all of that up with a four-year limited corrosion failure warranty.


Why Mercury

Perhaps one of the greatest things Mercury Marine offers is peace of mind with an unmatched dealer training and warranty program.

Mercury requires its dealers to employ technicians who meet a certain amount of training. Techs can even work their way up to "Master Technician" status. The customer benefits in the end because dealers have an incentive to employ better-trained techs: the better trained their techs are, the more the dealer gets back from warranty reimbursement.

"It translates into the fact that we've got better service," say Miller. "That is a result of better trained technicians, clean shops and parts in place when dealers need them."

The warranties Mercury offers also stand out in the industry. Most products have a standard three-year warranty, but quite often a promotional two-year warranty is added on for a total of five years of factory coverage. It provides the advantage of always having access to Mercury parts, service and customer support.

Maybe one of the biggest benefits of Mercury's warranty is that it's non-declining. You get the same amount of service on the last day of your warranty period as you did the first.

"I think it's a great advantage," says Miller. "It's a sign of confidence in durability and reliability in our products."

These innovations are some of the many that Mercury Marine has developed over the years. When you consider what they have done, it is easy to see why they are one of the leaders in the industry. For more information visit

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