原文地址：
http://madmariner.com/vessels/buying/story/OUTBOARD_ENGINE_BUYING_GUIDE_122208_VB?page=0%2C0
文章对各个主流品牌的船外机均有涉及，待我慢慢译来。
If you are looking at a new outboard-powered boat or considering repowering your current boat, you may be facing what seems a bewildering array of choices.
There are seven well-known outboard brands here in the United States, with several additional manufacturers whose brands are better known outside the country. There are a number of choices in almost every size category, and despite the predictions of some in the industry, you can still choose between two-stroke and four-stroke engines, at least for now.
Here's a look at what's available from the leading manufacturers, where outboard technology stands, and some suggestions for choosing what's right for you.
如果你在考虑购买新的机动艇或重新装备现有艇上的动力马达，你就会面对很多眼花缭乱的选择了。
在美国国内有七个知名的船外机品牌，还有一些国内不咋的但是国外却很有名的牌子。每一个尺寸都有很多个选择。不管这个机器以后会有什么新技术，至少在现在你只能在两冲程和四冲程里面选。
下面我们就看看这些领先世界的牌子有什么值得骄傲的技术，最适合你的又是哪些选择？
TWO STROKE VS. FOUR STROKE
The most obvious and significant trend in the outboard industry over the last 10 years has been the emergence of the 4-stroke motor as the dominant configuration. The major manufacturers estimate that as much as 70 percent of new-engine sales are 4-strokes.
Along with the emergence of the 4-stroke has come the modern electronic control module (ECM), used to optimize the combustion process in both 2- and 4-stroke engines. Interesting enough, 2-strokes, which required mixing oil and fuel in a specific proportion to be burned directly, were traditionally more popular. Their mechanical simplicity and light weight made them easy to live with – well, as long as you weren't breathing the blue-tinged exhaust.
As emissions standards began to tighten, new technologies, such as direct fuel injection, were developed. The epitome of the 2-stroke motor today is Evinrude's E-TEC line, which can provide many of the emissions and operating advantages of a 4-stroke motor, but without its mechanical complexity. Evinrude, a division of Bombardier Recreational Products, has essentially absorbed the former Johnson brand. The only model left from Johnson is a simple, carbureted 9.9-horsepower 4-stroke.
Most of the other major brands also still offer 2-stroke motors, in the higher horsepower ranks and all direct-injected. These include the Mercury Optimax, Yamaha HPDI and Nissan TLDI lines.
Five years ago, 4-stroke motors were just making their first significant inroads into the outboard market. Some of the disadvantages of the early 4-strokes, such as heavy weight compared to similar-horsepower 2-strokes and comparatively poor low-speed acceleration, have largely disappeared.
Some boaters still prefer 2-strokes due to their lighter weight and simple mechanical setup.Lightweight designs, incorporating features such as composite material air intakes, along with sophisticated computers to control fuel-delivery schedules and spark advance have leveled the performance field. Some specific markets, such as the bass boat community, still hold tightly to their long-held preference for 2-stroke motors. The saltwater, offshore-fishing community, however, prefers 4-strokes because of their fuel efficiency at high speeds and long-term reliability.
两冲程还是四冲程？
近十年来船外机行业的趋势是四冲程出现和流行。据主要几个厂家的统计，售出的新机器中70%都是四冲程。伴随着四冲程一块出现的技术是电子控制模块（ECM），可以使二冲程或者四冲程的机器燃烧更充分。二冲程的机器是一般说来要更普遍些，它需要将机油和燃油按一定比例混合再燃烧。机械上比较简单，重量也比较轻，除了忍受蓝色的废气，用它还是不错的。
随着对排放的限制，类似直喷这样的新技术就发展起来了。直喷二冲程机器的代表Evinrude的E-TEC系列，并没有复杂的机械原理，却在排放和操控指标上更胜于四冲程机器。Evinrude只是炮兵转民用产品的一个分支，吸收了老Johnson公司，而那时的Johnson只有碳化9.9匹的四冲程的技术。而其他的主要品牌也在供应二冲程的机器，马力较大而且都是直喷技术，包括Mercury Optimax, Yamaha HPDI 和Nissan TLDI系列。
5年前，四冲程的机器得到了极大的发展。早期四冲程机器的毛病，比如重量较大，提速较慢等现在已经可以被忽略了。它的轻量化设计，以及类似复合材料进气口，电脑控制的喷油量和火花提前等这样的合并技术大大拓展了它的表现空间。现在只有一些特定的市场，比如bass boat用户才会坚持使用二冲程。而咸水作业和海上渔业还是会选择四冲程，因为它们高速行驶下更省油，性能也更可靠。
EMISSIONS RULES DRIVE INNOVATION
A great deal of the innovation and success of the 4-stroke motors has been due to increasingly-stringent emissions regulations. The California Air Resources Board (CAR
has led the regulatory charge for the last dozen years.
The federal government has allowed California to set stricter pollution limits than the rest of the nation because of the severity of the pollution problem there. Given the size of the California market for everything from automobiles to lawnmowers to boats, "what is good for California" has typically led to standards we all must live with. Fortunately, we also get the benefits: outboard motors that pollute less and are significantly more fuel-efficient than the old blue-smoke stinkpots we used to lovingly coax into operation.
The CARB standards require outboard manufacturers to offer a product line that meets an average emissions standard across the line. That means they can still offer some of the less "green" motors, as long as they are offset by sales of motors with higher-than-required emissions certification.
It's safe to say that emissions standards are going to continue to tighten, requiring further technical innovation by manufacturers. Current standards are focused on carbon monoxide and oxides of nitrogen. Given the visibility of simple carbon dioxide's contributions to environmental problems, it's not much of a stretch to predict that exhaust product will be the target of tighter rules in the future.
Manufacturers are also innovating to increase fuel efficiency.
David Meeler, product market information manager at Yamaha, says the average boater is "very concerned" about fuel efficiency. "They're still using their boats, but…modifying behavior to accept the higher cost of fuel," he explains. "You'll see manufacturers paying more attention to it, developing engines as solutions."
排放政策催生了变革
很多技术变革和四冲程的大受欢迎都得益于日益严格的排放限制。在过去的十二年里，加利福利亚空气资源委员会引导了这项政策变化。由于该地区的环境污染形式严峻，联邦政府同意加利福利亚实行较其他州更为严格的排放政策。由于不论是汽车、割草机还是船只都在加利福利亚有相当大的市场，这样就出现了“加州用什么”我们全国就用什么的状况。于是，我们也幸运的用上了更清洁更省油的机器，否则还得忍受喷着蓝烟，排放恶臭的老旧玩意。
CARB（加州空气资源委员会）要求船外机生产厂家应该生产排放指标介于规定标准左右的的机器。这也就是说，厂家还可以生产销售那些略低于环保标准的机器，用来作为高环保标准机器的补偿。
可以保证的是以后的环保标准会越来越高，需要更多的技术变革。现在的环保标准只是盯着一氧化碳和氮的氧化物。考虑到二氧化碳对环境的影响越来越严重，那些非环保的产品将肯定成为未来政策的靶子。
船外机的生产厂家还在不断创新改善油耗。yamaha的市场信息部经理大卫米勒告诉我们，“现在普通的船主也开始关心油耗了”“他们不会更换船，但是却想要改变以前高耗油的状况”“很多厂家都注意到了这一点，作为对策，只能在船外机上做文章了”。
As an example, Yamaha just introduced a new F40, a 40-horsepower 4-stroke. "We added EFI (electronic fuel injection) to that; not only as an element of convenience in terms of ease of starting, but also increasing the brain power to monitor the atmosphere, fuel injection, and fuel mapping," Meeler says.
He says the new F40 provides maximum fuel economy and performance for an engine that size.
举个例子，yamaha刚刚上市了新F40，一块四冲程40马力的机器。米勒说：“我们用了EFI（电子直喷）技术。不仅更加容易启动，而且还可以智能监测空气，燃油喷射和燃烧状况等方面。”他还说新款F40在同级别的产品中是最省油，性能最好的。
多虧您熱心的翻譯
感謝。。
越多电子控制在机器上，越多容易坏的故障点要排查。这种小机器，越简单越好。
我要的就是这一贴