Dave Martin
Northern News Services

NNSL (Jun 22/98) - The workhorse of marine motors for small and medium-sized boats is the outboard motor. Here in the North they make sense because of their portability. They are simple to operate and convenient. Today's outboard motor is typically a high-revving, high output, two-stroke motor.

Unfortunately, it's also a sometimes bulky and always very smoky and inefficient polluter compared to its more mechanically sophisticated four-stroke cousin.

Two-stroke motors have been around for a long time. Millions are used in small applications such as lawn and garden machines as well. That's a lot of blue smoke and unburned oil being discharged into the environment.

That has not gone unnoticed by legislators in North America, and with ever-tightening emission standards the future of the two-stroke has until recently seemed bleak. That, however, is changing.

Four-stroke motors are available from several smaller brands like Yamaha, Honda and Mariner for years. They are alternatives, yes. But, the two titans with the largest stake in the two-stroke outboard marketplace have addressed the problems of two-stroke motors.

Both Mercury Marine and the Outboard Marine Corp. have introduced new technology to improve emissions compliance of two-stroke marine motors. Electronic fuel injection has been available on some selected models of motors. But until recently, fuel injection has not solved all the problems of the typical two-stroke.

Now, the OptiMax lineup from Mercury and the OMC FICHT-equipped outboard motors are setting the bar higher when it comes to efficiency and economy. Mercury Marine claims that their OptiMax line provides 40 percent better fuel economy, with smokeless and misfire-free operations. Mercury uses a direct injection system that was developed for outboards in partnership with Orbital Engine Corporation.

Using a high pressure plume of atomized fuel directly injected into each cylinder of the combustion chamber as well as electronic multi-point lubrication that delivers precise amounts of oil exactly where it is needed, these engines are said to "epitomize efficiency, use less oil and virtually eliminate smoking."

The technology is innovative. It's the first time you can run a two-stroke outboard motor that's basically smokeless. The emissions on them now are equivalent to a 4 stroke. It's extremely responsive because it's direct fuel injection. At idle speed, the fuel economy is up about two hundred per cent. At wide-open throttle, anywhere from five to 12 percent. In the mid-range throttle, where most people run, they're running probably 20 to 30 per cent improvement.

Outboard Marine Corp. has taken a different approach to the same problem. Nevertheless, their claims of improved efficiency and reductions in emissions are equally startling. Outboard Marine Corp. claims a reduction in fuel emissions by up to 80 per cent, lower oil consumption, and virtually smoke-free operation. All this in addition to "35 per cent greater fuel efficiency." Though the mechanical details of both systems are different, they are essentially high-pressure, direct injection systems.

Mother always said that if something sounds too good to be true, it usually is. When it comes to the new generation of outboard two-stroke motors, however, it seems like a win-win proposition no matter how you look at it. For the consumer the advantages include the ability to go farther on less gas, while exercising some care and concern over the environment.

If this new technology is adopted, then outdoor enthusiasts could expect to go farther on less money, conserve fossil fuel, and leave a smaller mark on the environment. For the moment, whether your brand of choice is Mercury or OMC, take heart that the two-stroke motor will be around for some time to come.