Suzuki DF300

Power trip

Suzuki Marine’s new DF300 proves that the most powerful four-stroke outboard in the world can also be lightweight, compact and streamlined, making it the ideal power choice for an increasingly popular class of offshore fishing boats, cruisers and power catamarans.

At 4lt, this new engine offers the largest displacement of any V6 outboard. The low-end grunt and torque to power heavily loaded offshore boats out of the hole is second to none. And the silky smooth acceleration keeps on climbing as you push the boat to its eye-watering top-end speeds.

Suzuki’s DF300 delivers all this power and performance in a package that fits with today’s modern fishing and performance boats. With a target weight of 274kg for the 25-inch shaft model (or 279kg for the 30-inch shaft), Suzuki’s 300hp four-stroke weighs about the same as other normally aspirated 250hp models. Features such as new Alumite-coated forged aluminium pistons, which are attached to connecting rods with full float hollow wrist pins, means the biggest motor in the Suzuki range boasts excellent weight-saving features without compromising performance.

“With the advent of these large displacement 300hp four-stroke outboards, many boatbuilders are now designing their boats to suit these fuel-efficient engines,” Haines Suzuki Marine general manager Greg Haines said.

“Boatbuilders and the public are realising the advantage of outboard power: increased cockpit space, reliability, weight savings, fuel efficiency and ease of maintenance.

“They are an attractive alternative to petrol or diesel inboard engines and we see the larger plate aluminium boats and power catamarans as being well suited.”

At the launch, twin DF300s on the back of a Powercat 3000 Sports Cabriolet highlighted just how explosive and powerful the DF300 is when paired with the right hull.

The DF300 was designed with a narrow 55-degree vee-block. This allows for the easy mounting of twin or triple installations on 26-inch centres without contact. Suzuki also uses an offset driveshaft on the DF300 for better balance on the transom and a compact design. For unsurpassed performance and fuel efficiency, Suzuki’s DF300 features a dual overhead cam (DOHC) powerhead with four valves per cylinder.

Suzuki’s proven variable valve timing continually adjusts the intake cam phasing to maximise torque in the low and mid range. This feature also reduces emissions and improves fuel economy – a bonus for offshore anglers who like to run fast and far in search of fish.

Suzuki’s clean-running DF300 has met the Environmental Protection Agency (EPA) 2006 federal emission standard and the California Air Resources Board (CARB) 3-Star Ultra Low Emissions rating.

The DF300 boasts other design features popularised by Suzuki’s four-stroke range, including computer-controlled multi-point electronic fuel injection for optimum performance, and a self-adjusting, oil-bathed timing chain.

It also introduces several important firsts for Suzuki Marine, beginning with a sleek, aggressively designed lower unit that aims to reduce drag. This hydrodynamic lower unit works in conjunction with Suzuki’s two-stage gear reduction for an aggressive final drive ratio of 2.08:1. This low gear ratio means the DF300 can swing a 16-inch stainless steel propeller from 17 to 26-inch pitch for optimum performance on a wide variety of hull shapes and styles. Counter rotation is available in both 25-inch and 30-inch shaft lengths for twin/triple engine configurations.

Newly configured air inlets feed an 81mm single throttle body for increased induction airflow. In another first, exhaust now flows unimpeded through the engine’s mid-section, as cooling water is routed through a separate track and expelled through a special vent above the propeller. These new intake and exhaust systems work together to improve the engine’s overall breathing for increased power output. And with a maximum operating range of 5700 to 6300rpm, boaters can wind the DF300 up for exhilarating top-end performance.

Suzuki says its engineers know how important a full arsenal of sophisticated electronics is to today’s modern fisherman, so they’ve included a powerful 12V 54-amp alternator that delivers plenty of juice to power up fishfinders, GPS chartplotters, radar systems, baitwell pumps, spreader lights, and more. The DF300 also features a dual circuit charging system that can be adapted to accommodate the dual-battery configurations often used on large boats. The system is designed to charge both the cranking and house batteries simultaneously but on independent circuits. Boaters can drain their house battery running trolling motors, electronics or pumps and still have a fully-charged cranking battery for the outboard motor.

The new DF300 is the first Suzuki to feature Suzuki Precision Control – a fly-by-wire shift/throttle system designed for single or dual helm installation, with single, twin or triple engine rigging. This new electronic control provides many performance advantages over conventional systems, including smoother, more decisive shifting and quicker throttle response, which is especially important when manoeuvring in and out of tight spaces. This system also provides easy electronic synchronisation of twin or triple engines for maximum engine efficiency while underway. Additional features that make Suzuki’s new DF300 easy to use and maintain include push-button starting, new easy-to-use cowling latches and front and rear freshwater flushing ports, so you can keep the inside as clean as the outside.