Next, ask yourself if, while passagemaking, you're going to need to remove the engine from the dinghy and store it on your larger cruiser. I'd say that the answer, in most cases, is likely to be yes, which means that weight will be a concern. This is a distinct downside to our evolution into four-stroke technology, since they're considerably heavier than their two-stroke counterparts. Our 9.9-horsepower collection averages 86.2 pounds in weight; that's a lot for the average person to manhandle without some assistance. Even stepping down to a 4-horse four-stroke doesn't offer much relief; these all weigh in somewhere between 55 and 60 pounds. If weight is your primary consideration, the Torqeedo could be a real option, since it tips the scales at 38 pounds. Torqeedo also makes a really small Travel motor that has the approximate power of a 3-horsepower engine; it weighs a mere 30 pounds, and that includes the weight of its lithium-ion battery.
Another area of concern is how an engine fits on the boat you're trying to propel, with transom height the key issue. Traditionally, companies offered two shaft lengths, a short and a long, measuring 15 inches and 25 inches, respectively. Now we're seeing manufacturers offering three shaft-length options. "Small Outboards at a Glance," the chart on page 105, shows that some of the models we examined now come in a third, 20-inch shaft length, although not those from Mercury and Yamaha. Torqeedo's two shaft lengths are unusual, measuring 25 and 30 inches. Shaft length significantly affects how well an individual motor fits on a particular boat.