Watch Your Wake!

In 1996, the EPA produced a document stating that gasoline marine engines are one of "the largest average contributors of hydrocarbon" emissions. In fact according to the EPA "of all categories of nonroad engines, recreational marine engines contribute the second highest average level of HC exhaust emissions. Only small gasoline engines use in lawn and garden equipment emit higher levels on average." Until recently, this industry was relatively unregulated by local officials but states like Vermont and Massachusetts have begun to adopt more stringent environmental regulations. Not only do these dangersous emissions created by smaller outboard engines cause irritation to the respiratory system, but the Vermont Department of Environmental Conservation estimates that carbureted 2-Stroke outboard motors never burn 20-30 percent of the fuel used to power them, that unburned fuel is reportidly excreted from the engine directly into the water.

In response to this hazard the EPA took steps to work with manufacturers to produce an outboard personal watercraft marine engine that is over 75 percent cleaner in 1996. Although this engine is reported to be slightly more expensive than older carbureted 2-stroke models, it is said to have a significantly better fuel economy, quicker throttle response, and easier to start.

In general, it seems to me that a 4-stroke engine for your crew is the responsible and environmentally friendly way to go. Although it has been reported that some 4-stroke engines do not accelerate as quickly and are certainly heavier than their 2-stroke counterpart, 4-stroke engines seem to outperform in every other category and contribute significantly less waste to the environment.

Options for more environmentally friendly engines? From all the literature I can compile it seems you now have 2 options when it comes to a friendlier engine. Direct injection 2 stroke engines, or modern 4 stroke engines.

As far as I can tell Tohatsu's TLDI engine is the only direct injection 2 stroke, small outboard engine manufacture; it comes in a 50 and 90 hp. However in one website that I visited this warning was listed on the site: "IMPORTANT NOTICE: ALL TLDI MODELS. DUE TO MANUFACTURER RESTRICTIONS WE ARE NOT ABLE TO SHIP ANY TLDI MODEL ENGINES. THIS IS DUE TO THE COMPLEX INITIAL SERVICING REQUIRED PRIOR TO CUSTOMER TAKING POSSESSION. TLDI MODELS MUST BE INSTALLED AT OUR COOKEVILLE, TN LOCATION. INSTALLATION (EST. $150-250) AND SALES TAX (9.75%) IS ADDITIONAL. SORRY, NO EXCEPTIONS." This is the 2006 version of this model so I have no idea if modifications have been made since then. The next smallest 2 stroke direct injection engine that I have been able to find on the web is the Mercury Optimax that comes in 135-225 hp.

With most rivers converting to wakeless launches that are generally larger and nearly impossible to drag out of the water anyway, it seems the way of the future is the 4-stroke engine. The leader in 4-stroke engines according to the Powerboat Training Website is Honda.

To be completely honest, any feedback on this article is more than welcome. Admittedly, I am learning as I go, but it seems to me, if you own a 2-stroke engine manufactured before 1996 or any 2-stroke that is not a direct injection model, you are causing some serious harm to the river and possibly contributing to respiratory problems to your coaches, rowers, and coxswains.