Yamaha releases new technology

YAMAHA has announced the release of its new V6 four-strokes and the all new four-stroke F70 outboards. 

The V6 four-stroke F300, F250, and F225 are based around a newly developed 4.2L 60 degree V6 engine. A double overhead camshaft design matched with variable camshaft timing produces, according to Yamaha, unbelievable performance and fuel economy.

By using a highly-advanced thermally-applied plasma fusion process on the cylinder walls, Yamaha's new line of V6 Offshore outboards now have cylinder walls that claim to be 60 per cent harder than steel. That means larger cylinder bores for increased displacement, resulting in more power and torque without increasing outer cylinder dimensions.

This also means dramatically lighter weight. These three new models in this range weigh less than Yamaha's current 3.3 litre F225, and according to Yamaha, far lighter than any competing four-stroke model. Weight is now comparable to direct injected two strokes but the new range offers substantially larger capacity. The plasma fused cylinders also result in better cooling and the "micro-textured" cylinder walls help decrease friction and further increase performance and enhance reliability.

More grunt from larger capacity means a lower 1.75:1 gear ratio has been employed on these engines. This allows the new offshore V6s to spin a larger propeller for better hole-shot performance while the variable camshaft timing provides crisp acceleration and great fuel economy right through the rpm range.

The F300, F250 and F225 utilise "drive by wire" control systems for smooth throttle operation and responsive performance while also providing secure and reliable shifting. The engines also feature a patented shift dampening device that eliminates the noise that sometimes occurs when engines are shifted in and out of gear.

The new Yamaha V6s are compatible with brand new instrumentation in the form of a five inch colour LCD screen with a range of display options for the outboard and the boat. The display has the ability to connect and display information from up to three engines.

The new F70 is a further development of the F60, sharing the same displacement and stroke. Yamaha said the engine is lighter than any competitive four stroke, or direct injected two stroke motor in the 70 - 75 horsepower class. The F70 achieves this by its unique four valves per cylinder design activated by a single overhead camshaft rather than the conventional dual camshaft design for 16 valve engines. This reduces the weight that would result from having an extra camshaft and the components that go with it.

Four valves per cylinder have dramatically increased this engines volumetric efficiency - the efficiency with which the engine can draw fuel and air in and push exhaust out of the cylinders. Increasing this efficiency means the F70 is able to run at a higher RPM with the max operating RPM being increased to 6300rpm.