New outboard technology displays maximum grunt

High-tech advances mean cheaper to run outboards for recreational boaties. ROBIN BAILEY reports.

Yamaha showcased the world's most advanced outboard technology to New Zealand's boating media this week, demonstrating its new generation of low-emission engines on a range of local boats.

Yamaha chose New Zealand boats for the exercise, with the biggest, a 13m Rayglass Protector RIB, underlining a commitment to New Zealand America's Cup campaigns which dates back to KZ7 in Perth in 1987.

The new Team NZ chase boat is powered by twin F225A four-stroke outboards, and is expected to log thousands of hours of running before the next Cup defence in 2003. Reliability, economy and smooth running will be important contributors to the performance of Team NZ's on-water support.

The F225A is Yamaha's largest four-stroke outboard and evidence of its intention to provide a full range of four-stroke outboards, as well as the two-stroke lineup that includes the low-emission HPDI (high pressure direct injection) models.

Journalists were also able to test these new-generation, low-emission two-stroke series, with 150hp HPDI's fitted to Protector 750 patrol boats and Buccaneer 635 Excess runabouts.

This new-generation lineup is the result of a huge investment in new technology made by Yamaha over the past five years. That includes construction of the world's most advanced engine manufacturing plant, Kumamoto Products in Japan, which opened in 1998 and increased the company's capacity by 100,000 units a year.

The investment has also seen the four-stroke range increase to 12 engines from 4hp to 225hp. The 4hp is recognised as the Guinness world record-holder for fuel economy - having travelled 58.45 nautical miles on a single gallon of fuel in the Orakei Basin in 1999.

The investment by Yamaha has come partly in response to tough new emission regulations in the United States, known as the EPA 2006 standards, which will tighten the allowable emissions for outboard motors in 2006.

Although it wasn't the first to introduce direct injection, Yamaha's HPDI is the only high-pressure system, operating at more than twice the pressure of other outboard injection systems.

By developing purpose designed and built engines, as well as a new generation of injection technology, Yamaha's HPDI's offer fuel saving through the speed range to the highest levels.

When the Auckland Coastguard changed to HPDI engines late last year, it saved $2000 of fuel on its Rescue Alpha patrol boat in just three months.

While Yamaha has responded to this challenge with HPDI and four-stroke outboards, it has also been conscious of the increasing environmental awareness around the world.

So while it developed the HPDI technology, Yamaha continued to produce four-strokes to take advantage of the economy, low noise and low emission features of this engine configuration. Already the first in the world to develop a four-stroke outboard in 1984, Yamaha increased its range to include almost every standard horsepower size.

Advances in technology see the new Yamahas tip the scales at a similar weight to the equivalent two-stroke. Advances in metallurgy, design and innovations such as the F225A's "in-bank exhaust system" have brought about power-to-weight ratios that were previously only dreamed of.

Either way, the recreational boater comes up smiling. The new-technology engines have made it economical to run large, trailerable boats that can be kept at home or at a beach house.

Better economy means the boats are cheaper to run - as opposed to the expense of running the big V6 outboards of the past - and can travel far further on the same tank of fuel. At lower speeds there is minimal smoke and engine fuming, a bonus when trolling for trout or game fish. Yamaha's development has also reduced noise levels.

Similarly, the four-stroke targets the same parameters of performance, reliability, low emissions, low noise and spectacular economy. Where the new Yamahas succeed so well is doing all these things, while keeping the weight to levels comparable to two-strokes of the same horsepower rating.