FOND DU LAC, Wis. — Mercury Marine has further buttressed its second generation of mid-range outboard offerings with three new engines — 75-, 90- and 115-hp 4-strokes — and unveiled its first in-house-built sterndrive engine, a 4.5-liter 250-hp MerCruiser.
“These engines are a result of a tremendous amount of consumer research and development activity by [our] team and we are proud to unveil them here and have you put them through their paces,” Mercury president of global sales and marketing Kevin Grodzki told about 40 journalists at an early summer press introduction at Mercury’s headquarters in Fond du Lac and nearby Oshkosh.
Mercury’s previous Gen II 4-stroke introduction was the 150 FourStroke at the 2012 Miami International Boat Show. Mercury builds the 4-cylinder outboards on a block with a 2.1-liter displacement and a low weight of 359 pounds (20-inch shaft) for their horsepower, Grodzki says.
Yamaha’s recently introduced F115 has a listed weight of 379 pounds for its 20-inch shaft model. The previous Mercury 115-hp 4-stroke (1.7-liter displacement) weighed 399 pounds, and the current 2-stroke Mercury OptiMax (1.5 liters) comes in at 375 pounds.
“The combination of good performance and lower weight is a tough balancing act,” says Mercury vice president of product development, engineering and racing David Foulkes. “We think we’ve done a very good job with this challenge. It is very difficult to deal with this tradeoff of displacement and weight.”
More displacement means greater torque and increased acceleration. The engine’s “giddy-up” even exceeds the OptiMax’s acceleration because of its tremendous hole shot, which Foulkes referred to as “low-end torque peak.” “The 75 and 90 also have this great low-speed torque for that greater acceleration,” Foulkes says.
The performance improvements open this engine to new markets, Foulkes says. “Boats like large pontoons might have been out of reach for this class of outboard — not for this [engine],” he says.
An optional gear case, labeled the “Command Thrust,” measures 4.9 inches in diameter, compared with the standard 4.2-inch diameter, and this lower unit touts a deeper gear ratio. Both attributes allow Mercury to fit the outboard with more props.
“We can use the same prop line as we do with our 150 FourStroke,” Foulkes says. Mercury also focused on harnessing vibration and keeping noise levels low. Maintenance loomed large, too. The engine valve train requires no maintenance and its information panel under the cowling comes with a QR code for mobile devices that calls up Mercury maintenance videos ranging from oil changes to winterization.
The 4-strokes are available to dealers and builders. The sterndrive will hit the market in September.
‘Not just another sterndrive’
The new 4.5-liter sterndrive shared equal stage time with the 4-stroke platform at the June 18-20 event, which gave journalists a chance to test the engines. Mercury said last year that it would begin to develop its own engines, separating itself from the automotive market.
“With outboards we have always had the luxury of deciding what technology we wanted in our engines, and now we can do the same with our sterndrive engines,” Foulkes tells me. “The direction of the auto engines was not fully serving our customers. We are now able to give them features that are built into the engine exclusively because they are marine engines.”
Case in point is the position of the new MerCruiser’s throttle body. It faces aft instead of forward. “With the previous engines the throttle body was always facing the driver, and so was the noise that was being generated,” Foulkes says. “Now we can direct that noise aft and away from the driver.”
Mercury Marine president John Pfeifer told me that the company will spend the next few months making sure dealers, their customers and boatbuilders know without a doubt that Mercury makes the 4.5.
“We need to make it clear that this is not just another sterndrive,” Pfeifer says. “It represents a big change in course for the industry. We’re holding events in a lot of different locations. We started in the Keys down in Florida, where we brought some customers together to show them exactly how we design the product and how we build the product.”
The sterndrive’s design innovations include a long runner scrolled intake manifold and high displacement, which produces an outstanding power-to-weight ratio, Mercury says. The V6 engine weighs 130 pounds less than a 5.0-liter V8 small block, but delivers similar performance, the company says.
The aft-facing throttle body, anti-whistle throttle plate, engine cover and mounts, lightweight flywheel, fuel supply module and structural oil pan contribute to smoothness and low noise and vibration, the company says.
Mercury says it uses durable cast-iron components wherever the engine encounters seawater, and corrosion-resistant aluminum and composites elsewhere.
The 4.5-liter engine can be teamed with Alpha and Bravo drives.
The MerCruiser is compatible with SmartCraft Digital Throttle & Shift and Mercury’s Joystick Piloting.
Eighteen boats were on hand for journalists to test. A pair of the new 4.5-liter engines powered a Sea Ray 310 Sundancer, which I piloted for 20 to 30 minutes on Lake Winnebago. The Axius sterndrive joystick system was installed in the boat, which worked well, and I engaged the engine’s “Adaptive Speed Control,” which automatically maintains the set rpm point, regardless of load or hull position changes common in tight turns, tow sports and lower speeds on plane. I carved out a few donuts in both directions, and the two rpm gauges held steady at my chosen 3,000-rpm setting. Pretty neat.
The engines pushed the boat onto plane without a huff or puff. The 250-hp motors were relatively quiet and accelerated nicely in the mid-range. In the engine compartment I saw that all of the maintenance points are right in front of you, within easy reach. The block’s forward top section also held the same label with QR code as the outboards. Mercury refers to the QR code as the “Weekend Saver.”
“If an alarm goes off, such as it would for low drive lube, you scan the code and go to the [Mercury website], where you’ll find out where the drive lube is located; you put a little lube in, and problem solved — no taking the boat to the dealer for help,” Daniel Clarkson, Mercury director of application engineering, says as he stands in the Sea Ray’s engine compartment.
I tested the 115 on a few boats, including a Carolina Skiff 218 DLV, a 20-foot center console and a Mercury 570 RIB, an 18-foot center console. Acceleration stood out as the most impressive performance characteristic. Man, I could feel that “low-end torque peak.” The engines emit a smooth but strong sound, and I could barely feel the engine vibrate while at idle when I put my hand on the cowling. With its single latch, the hood is easily removed and the oil fill dipstick and filter are staring you in the face.
It was an impressive three-day showcase of new engines and technology. I am hoping Mercury will unveil more new products — with that same low-end torque peak — during the fall and winter boat shows.
This article originally appeared in the August 2014 issue.