Marine Repower of a Dyna 53

The John Deere-powered Five O’clock Somewhere, a Dyna 53 yacht sails the open sea.

It is a typical picture-postcard day on the waters off North Queensland, northeast Australia, as Five O'clock Somewhere is put through its paces with a pair of new John Deere 9.0L engines. With owner Michael Day at the helm, the yacht is an eye-catching sight, slicing effortlessly through the sparkling sea at a gentle 25 knots, a quiet baritone hum issuing from the exhausts.

The Five O'clock Somewhere is a Dyna 53, luxury 18.5-meter (60-foot) fiberglass yacht with two cockpit levels and a spacious aft master cabin. When Michael Day bought it, repowering the 30-year-old vessel was one of his first priorities.

Brad Belcher of Belcher Diesel Service PTY Ltd. in Garbutt believed twin John Deere PowerTechTM 6090SFM85 engines would be the ideal solution. Compared to the old two-stroke diesels, the new M5-rated variant would offer cleaner, Tier 3/Stage III A technology, smoke-free operation, and an extra 75 kW (100 hp) each.

The new engines did not disappoint. "From the first time we took her out and pushed down the throttles on the John Deere engines, we just looked at each other and couldn't believe the difference," says Belcher. "The power delivery is so smooth; it's like a completely new boat." Belcher and Day agree that the low-revving, high-torque delivery of the 9.0L engines was instantly obvious. "The first thing you notice is zero vibration and a power curve that simply doesn't have any flat spots," says Belcher.

Engine refit on the water/strong>

For the engine refit, Belcher and his team went above and beyond to repower Five O'clock Somewhere on the water at a service pontoon in the marina. While it saved thousands of dollars in slipping costs, it was a logistical challenge. "We had to balance the crane, and time the removal and installation of the engines perfectly because of up to 4-meter (13-foot) tidal ranges," Belcher notes.

Belcher's team installed electronic controls on the flybridge and docking controls in the cockpit and engineered a stainless exhaust system to ensure correct breathing and backpressures. They developed new engine beds and custom transmission brackets to cradle the engine and ZF 305-3A gearbox packages. With the old engines and generator out, the team also renewed seawater strainers and primary fuel filters and replaced water tanks. For optimal performance, they coupled the new marine engines to transmissions with a 2.250:1 ratio, and customized transmission oil coolers to help keep the engines running smoothly in North Queensland's warm waters.

Brad Belcher standing next to twin John Deere PowerTechTM 6090SFM85 engines in the engine room of his Dyna 53 yacht.

"A smooth-running marine engine for years to come"

According to Belcher, the 9.0L engines are smart, powerful, easy to maintain, and offer good fuel efficiency. "During unofficial testing with full fuel and water tanks, Five O'clock Somewhere clocked a 27.5-liter (7.26 U.S.-gallon) per hour/per engine fuel burn for 10 knots at 1500 rpm. While the engines can consume up to 115 liters (30.4 U.S. gallons) per hour at 2500 rpm, on the day of running they consumed around 11 liters (29 U.S. gallons) per hour at 23 knots into the breeze and against a small tidal run at 2500 rpm," Belcher says.

"Any boat without good marine engines is really just a bucket"

Happy owner Michael Day is enthusiastic about the repower. "I'm extremely pleased with the outcome," he says. "Engines are the heart of any boat. The engine refit has shown that any boat without good engines is really just a bucket."

With the new engines installed, Day and his family will spend weekends pointing the Five O'clock Somewhere out toward the pristine waters of the Great Barrier Reef, a two-hour plus run off the coast. And longer trips of four to five weeks are in the cards as retirement brings more time to enjoy the pleasures of yachting on Australia's beautiful waters.

Engines are the heart of any boat. The engine refit has shown that any boat without good engines is really just a bucket.

Michael Day

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