I had a chance to put about 20 hours of hard and fast (40-to-50mph) ocean running time on Suzuki’s DF350s down in Key West running 150-175 miles a day on a 36 Yellowfin CC and a 35 Contender CC with Capt RT Trosset and his son Capt Chris. The speed, fuel efficiency, traction and smooth, reliable performance of these contra-rotating, twin-prop powerplants literally blew me away. Suzuki’s new DF300B is built on the identical 4.4L V-6 powerhead, albeit slightly detuned to achieve its 300HP status. With the minimal horsepower difference between the DF350A and the latest DF300B, you might ask, “Why is this engine even necessary?” The easy answer is that a significant number of boat transoms are limited to either 300HP in a single configuration or 600HP for twins. The introduction of the new DF300B solves both problems very nicely and Suzuki did not have to “reinvent the wheel” in the process.
The DF300B provides superior “grip” on the water when boaters hit the electronic throttle control. This translates to superior performance from start to finish, with improved hole shots, stronger mid-range acceleration, improved top-end speed and enhanced low-speed maneuvering. With the engine’s power distributed over six blades, rather than three, Suzuki is able to reduce the size of the gears and create a sleek, hydrodynamic lower unit that slices through the water with minimum drag.
The DF300B’s robust 4.4-liter displacement features a 10.5:1 compression ratio and dual fuel injectors per cylinder for optimum performance and efficiency while using 87-octane gasoline. By using two smaller fuel injectors, Suzuki delivers a precise amount of fuel to the center of the combustion chamber, improving atomization and avoiding off-center combustion, a common cause of engine knock.
The DF300B features the offset driveshaft engine layout found on other Suzuki outboards, allowing for an overall compact design, along with two-stage gear reduction (2.29:1) for plenty of low-end torque without sacrificing top-end performance. This compact size, light weight (727 lbs. for 25-inch shaft model) and easy integration with Suzuki Precision Control drive-by-wire throttle and shift controls make the DF300B a clear choice for rigging on a wide variety of boats in single or twin installations. The Suzuki DF300B is available in either black or white, to better match the look on your transom. For more information, visit www.suzukimarine.com.