Complete Guide To Outboard Engines
The outboard engine gets its name from the fact that it is mounted "Outboard" on the transom of the boat. On some vessels there may be extended "brackets" for mounting the engine. Certain ones of these extended brackets may be able to raise or lower the elevation of the engine. They are called "jacking plates."  The outboard engine can be anything from mild to wild. It can troll at one mile per hour and five hundred RPM. It can run over 150 miles per hour and on occasion, I have seen them turn in excess of 15,000 RPM. The choice of type and purpose for which the engine is used are strictly up to you.  The fisherman can travel in a silence that permits deep meditation and the racer can run at speeds that raise the hairs on your neck, all with a two-stroke engine. A six cylinder, two stroke engine, turning 9,500 RPM, produces 57,000 explosions per minute! The sound is like all the little hounds from hell, turned a loose at once. The speed of a hydroplane is intoxicating like a fine wine, but it is dangerous, and it is expensive. In this book we will tell you about all of them, the fast and the not so fast.  Of course, the outboard mounted engine may have a two-stroke or a four-stroke power head. In fact, the lower units or gear cases are essentially the same for either engine. The mounting brackets and tilt/trim units are, for the most part, identical. The midsection and the power heads for the two-strokes are different. It is an understanding of the two-stroke cycle mystique which prompts this book, however, and to that end we will pursue two-stroke technology. The two-stroke power head is in a state of flux. Some say it is on the way out, but do not write it off just yet. At a recent test site where we were testing pontoon and deck boats an engineer from Mercury Marine suggested that a "possible alternative" to the four-stroke engine was suggested by the new clean burn outboards using Opti-Max technology.  His point, and one well taken, was that it is easier to pursue one type of power head and one technology than to try to develop engines in two separate styles. It is also cheaper. This approach seems sound and practical if the EPA requirements can be met. Mercury engineers have a way of making the difficult seem entirely plausible. Pollution laws certainly do not favor the two-stroke as it has been configured in the past, for it has been an inherently dirty engine. Direct Fuel Injection (DFI) may well clean up and extend the life of the two-stroke engine. Other technologies, only hinted at by the manufacturers, may give it life anew.  The lack of any practical four-stroke power heads in the upper horsepower classes, engines of 150 horsepower and above, makes that two-stroke a necessary commodity. High cost and excessive weight on existing engines has further conspired to delay the invasion of the four-stroke outboard. Before they totally displace the two-stroke engine they have much to prove. Regardless of what may be contained in the final chapter of the two-stroke story, I for one, shall never forget the engine. It is almost as much a part of me as an arm or leg and it has provided me with memories that I will take to the grave. It was on the Tensaw River of Alabama that I first ran a 5 horsepower, 4 cylinder, opposed piston, Evinrude outboard engine that belonged to my father. There were so many fish then that no one can describe the situation. You would just have to be there. I spent many quiet hours on that river and then one day I climbed into my first hydroplane. It was a Fillinger "D" boat. I took one look at that rooster tail and I was forever hooked. I still love the sound of a high-winding engine when it is running right at the edge of the possible. Stay with us and we will tell you all about two-strokes, how they run, why they run, and why sometimes they do not run! One chapter and a few references to four-stroke outboards will be made in this book but they will only be for comparison purposes.  For a good reference to four-stroke theory and operation, see COMPLETE GUIDE TO GASOLINE MARINE ENGINES which is available from BRISTOL FASHION PUBLICATIONS at P. O. Box 20, Enola Pennsylvania, 17025-0020