[herblevictoria]

Performance, responsiveness and lighter weight along with developments in technology such as direct injection and product specific enhancements have made the modern two stroke engines a viable and intelligent choice. This modern technology dispels the common perception of two stroke engines and has brought them to the forefront of technology and outboard selection. With best-in-class emissions, outstanding fuel economy, lower maintenance costs and high performance these engines deserve serious consideration.

[edwinc112]

While many of the conceived disadvantages of the two stroke outboard have been answered, many of the advantages hold true today. The simple fact is that the physical engineering of the two stroke engines allows for less parts and as a result less weight and physical size, along with simpler, less expensive maintenance. Unlike the four-strokes, a two stroke engine does not need oil changes every 100 hours or every season. The design of the motor does not require all the parts or the maintenance of parts you would be required to have with a comparable four-stroke. Motors such as the E-TEC do not require a break-in period or 100-hour services and in fact have a 3-year or 300-hour service period. In the long run this can equate to substantial savings over a comparable four-stroke and can avoid post purchase realization of service requirements and costs. Some models of two stroke engines even have the ability to self-winterize with a simple procedure at the throttle, taking just a few seconds. Many would argue that the modern two stroke engines require less maintenance than older two stroke engines and less maintenance than current four-stroke motors.

[Gespenster]

Another misconception two stroke motors have endured is that of being threatened by ever increasing EPA emissions requirements. According to top officials at Evinrude and other manufacturers, this is not a problem. Current offerings such as the Mercury OptiMax, Evinrude E-TEC and those from Tohatsu all surpass emissions expectations for 2013. As technology advances these motors have the capability of being improved further as requirements dictate and these companies are already working to meet future requirements. The fact is that if outboards of the future require such devices as catalytic converters, they would in fact be at an advantage, as even with these devices attached they would be lighter and smaller than most four-strokes with the same requirement. [links]

[sleasalo]

There are a few manufacturers producing modern two-stroke motors that have each answered many of these misconceptions with their own technology and have in turn created new two-strokes that are quiet, clean-burning, smooth and very fuel efficient. Motors by major brands such as Evinrude, Mercury Marine and Tohatsu are currently being manufactured for the US market in two-stroke models. The common factor between all of them is that the carburetor has been replaced by different forms of direct fuel-injection. Direct injection, or DI, has become the game changer in two-stroke motors. This has resulted in a cleaner, more fuel-efficient operation that meets today’s tighter EPA emissions guidelines. By injecting pressurized fuel directly into the combustion chamber of each cylinder, the precise amount of fuel ignites easily and is burned efficiently in the combustion chamber, with virtually no wasted fuel and cleaner exhaust. With direct injection there is no polluting un-combusted fuel leaving the engine. In fact, in today’s two-strokes there also is a complete burn of oil, resulting in much cleaner emissions and better fuel and oil economy.

[lightbox]

In last month’s article we discussed the basic differences in how two and four stroke outboards operate and some of the common perceptions of each of these motors. This month we will attempt to dispel some of the misconceptions of two stroke engines and explain the technology behind these modern outboards. Next month we will take a look at “Dispelling the Myths of the Modern Four Stroke Outboard Motor”

[JustGamerS]

Companies have such faith in the future of two-strokes that they are utilizing them exclusively in their outboard line and are even extending this new technology to other markets.

[bitboy]

Can motors/engines manufactured prior to 2006 be modified so as to be EPA 2006 compliant?
No. The new technology developed by the marine industry cannot be retrofitted.

[taiki]

Do the new regulations affect all watercraft?
No. Only NEW outboard and personal watercraft engines are affected. Emission standards have not been set for sterndrives and inboard engines due to the inherently clean nature that the technology of these engines provides. here

[Cynosure]

The United States Environmental Protection Agency�s gasoline marine final rule, published in August of 1996, establishes hydrocarbon emission standards for 2006 gasoline marine engines. Covered by the rule are outboard engines and gasoline marine engines used in personal watercraft and jet boat applications. The upshot of this mandate is that as of 2006, any and all NEW outboard marine engines must be manufactured to meet EPA emission standards. (Low pollution outboards will come as either four-stroke or direct fuel-injection two-stroke engines.) �Conventional� motors/engines manufactured before 2006 are exempt from the new emission standards.

[mhatta]

Are you confused by the United States Environmental Protection Agency�s regulations regarding hydrocarbon emission standards for outboard marine engines? [links]

[Vinnie]

Stowaway Marine has responded to customers� questions on this matter, specifically the question of whether two-stroke marine engines can still be used. Many believe that the two-stroke marine engine has been "banned". This is not the case and we hope the following will clarify the issue for you.

[greigmare64]

Do you have to buy a new motor/engine in 2006?
No. The regulations apply only to engine manufacturers. Boat owners and boat dealers are not required to modify their current engines to meet the new standards, nor will they be subject to any penalties. It would be wise to note, however, that the new generation of outboard and personal watercraft marine engines are over 75 percent cleaner than current marine engine technology. In addition to being more environmentally friendly, the new engine technology will provide boaters with many performance advantages, generally providing easier starting, faster acceleration, quicker throttle response, and a reduction in smoke, fumes and noise. Significant improvements in fuel economy could provide hundreds of dollars in fuel savings. [links]

[arturekert02]

Appreciate all of the responses.

[gue5tgue5t]

I've seen a little about 2-strokes bing banned. Is this true for San Diego and Mission bays? Just fresh water. Is there a grandfather clause?

[tomdetroit]

The law prohibiting their sale (as new engines) is actually a Federal law - CA liked it so much they adopted it as a state law and implemented it sooner than required by the fed's to speed up the reduction in air pollution. However, because it is a federal law, it applies to the entire US. I beleive that the rest of the US catches up with CA (no more sales of new carb'ed 2-strokes) in 2008. more

[richardfields112]

I was reading up on the sticky at the top of this 2 stroke section and it said one of the differences between 2 stroke and 4 stroke was that 4 stroke used separate oil and gas and 2 stroke used a mixture of oil and gas.

[morize]

My problem is, the people I bought it from said it was 2 stroke and gave me some 2 stroke engine oil to put in the oil tank. Should I be using 4 stroke engine oil because this engine can't possibly be 2 stroke?

[Richard]

In a possibly unrelated note, when i filled the oil tank from what seemed to be a little over half full to 3/4 full, I can't help but notice I seemed to have lost about 2-4mph top speed. Any thoughts? more