Club Marine was invited to sample the new powerplant, as well as a number of other 2007-spec Suzuki engines at the launch of the new flagship engine, held at the Couran Cove Resort on Queensland’s South Stradbroke Island.
Suzuki says its 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 saltwater heavy hitters – offshore fishing boats, cruisers and power catamarans.
At four litres, Suzuki says the DF300 is the largest displacement V6 outboard ever made.
With a weight of 274kg for the 25-in shaft model (or 279kg for the 30-in shaft), the new engine weighs about the same as other normally aspirated 250hp models, according to Suzuki, and is considerably lighter than any supercharged four-stroke of 200hp and up.
“With the advent of these large-displacement, 300hp, four-stroke outboards, many boat builders are now designing their boats to suit these fuel efficient engines,” said Haines Suzuki Marine General Manager, Greg Haines.
“Boat builders and the public are realising the advantage of outboard power; increased cockpit space, reliability, weight saving, fuel efficiency and ease of maintenance,” he added. “They are an attractive alternative to petrol or diesel inboard engines and we see the larger plate aluminium boats and power catamarans being well suited.”
The DF300 was designed with a narrow 55-degree V-block. The narrow design allows for easy mounting of twin or triple installations on 26-inch centres without contact. Suzuki also uses its offset driveshaft on the DF300, for better balance on the transom and an overall more compact design.
The DF300 features a dual overhead cam (DOHC) powerhead with four valves per cylinder. Suzuki’s Variable Valve Timing (VVT) continually adjusts intake cam phasing to maximise torque in the low- and mid-range. Suzuki says VVT reduces emissions and improves fuel economy, which is a big plus for offshore tournament anglers, who like to run fast and far in search of fish.
From an environmental perspective, the DF300 meets the US EPA 2006 Federal emissions standard and the California Air Resources Board (CARB) 3 Star Ultra Low Emissions rating.
Other features the DF300 shares with the rest of the big four-stroke Suzukis are computer-controlled, multi-point electronic fuel injection for optimum performance and a self-adjusting, oil-bathed timing chain.
The DF300 also introduces several important firsts for Suzuki Marine, beginning with a sleek, aggressively designed new lower unit that reduces drag by 18 per cent, according to Suzuki. The 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 ratio means the DF300 can easily swing a 16-in stainless steel propeller from 17- to 26-in pitch, for optimum performance on wide a variety of hull shapes and styles, says Suzuki. Counter rotation is available in both 25-in and 30-in 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, says Suzuki. And with a maximum operating range of 5700 to 6300rpm, there is more than enough oomph when you need to cover a lot of water in a short time.
A powerful 12V 54A alternator delivers plenty of juice to power up the increasing range of electronics now deemed necessary on today’s hi-tech fishing platforms and the DF300 also features a dual-circuit charging system that can be adapted to accommodate the dual-battery configurations often used on larger 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 starting the motor.
The new DF300 is the first Suzuki to feature Suzuki Precision Control – an advanced fly-bywire 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, says Suzuki, including smoother, more decisive shifting and quicker throttle response – especially important when manoeuvring in and out of tight spaces. Suzuki Precision Control also provides easy electronic synchronisation of twin or triple engines for maximum engine efficiency while underway.
Additional features include push-button starting, new easy-to-use cowling latches and front and rear freshwater flushing ports, so the inside can be kept as clean as the outside.
We had the opportunity to sample a twin engine rig during the launch and, while time was limited, I can say that power certainly wasn’t. With 600hp hanging off the transom of the Powercat 3000, available power was practically everywhere throughout the rev range. Throttle response was just this side of awesome and the DF300s felt smooth as a baby’s stern from idle to wild. They were also exceptionally quiet, which is to be expected nowadays from most top-of-the-line outboards.
Recommended retail price for the DF300 is as follows: $32,000 for the 30-in standard unit and $32,800 for the counter-rotating version.
Contact your nearest dealer for further information.