The other main spec to take into consideration is the shaft length. On outboard motors, this measurement is customized to fit 15, 20 or 25-inch transoms (the stern of the watercraft). When the shaft length is too long, there will be drag, while if the shaft is too short, it could lead to ventilation or potentially the overheating of the engine.

While both inboard and outboard motor can be raised, outboard motors also tilt forward, making them ideal for navigating shallow waters. Outboard motors can also be removed more easily, which is convenient when it comes time for storage. This capacity for removal and their lightweight design also makes out outboard motors easy to repair.

When comparing the two, the most discernable difference for most people is how you mix the gasoline and outboard motor oil. In a two-stroke engine, the oil and the gasoline are mixed together, whereas they are held in separate compartments in a four-stroke. This design makes the two-stroke simpler but provides better lubrication to the four-stroke.

First of all, and probably most importantly, they are the cheapest option. They also tend to be lighter, and you can easily remove them when not being used, making them simple to replace as well. Traditionally, outboard motors were two-stroke, which meant that you had to mix the outboard motor oil and the gasoline; however, today there are several four-stroke options.

Before embarking on the first boating trip of the year, I always check the fuel line for cracks, wear and loose attachments. I also check the tanks for any damage and ensure that there isn’t any water in the fuel. And, of course, I always double-check the levels of fuel and outboard motor oil.

The fact that boats often go weeks, months or, in some cases, even years between uses doesn’t bode well for them either. Because of these constant strains on the engine, it is crucial to perform routine maintenance and change your outboard motor oil frequently. This will not only improve your boat’s performance, but will also prolong its life.

While Evinrude may get a lot of publicity, Mercury Marine is actually the world’s leading manufacturer of marine propulsion engines. Unlike other companies that produce complete watercrafts, Mercury focuses exclusively on engines, providing units for recreational, commercial and government usage. The company creates both Mercury and Mariner engines.

You won’t see Mercury Marine on the NYSE, but that’s because they are a division of Brunswick Corporation, who also owns Bayliner, Sea Ray and other leading marine manufactures. In addition to their award-winning engines, Mercury also produces a wide line of accessories and Mercury oil. The Mercury Marines mission statement outlines their commitment to excellence and their customers.

In Europe, this group is comprised of 13 major manufacturers and known as the European Automobile Manufacturers Association, or the ACEA. Their US counterpart, the American Petroleum Institute (API), includes over 400 corporations and is responsible for producing service categories. In additions to the API, the US also has the American Society of Testing and Materials (ASTM), which set limits on oil quality. Tomorrow we will go into more specifics about each organization and take a closer look at the information they provide.

Most manufacturers recommend changing your outboard motor oil and filter after every 100 hours of use or every season, which ever comes first. Some people may postpone this task, but it is essential if you want to prolong the life of your boat and achieve optimal performance. Changing your oil may seem daunting, but with a few wrenches and some knowhow, you can get the job done in no time.

Always remember to drain all of the old oil before refilling the crankcase. Mixing old and new oils will leave deposits in the system and limit the effectiveness of the new oil. Also, be sure to add a quart of oil for the new filter and run the engine when you are done to ensure that the oil pressure is correct and there are no leaky areas.

Outboard boats tend to be less expensive and our good for fishing and other leisurely water activities, while an inboard is a near necessity for extreme water sports. In this down economy, many people are considering buying a used boat and saving some money. If you are considering this route, put the boat through a strict vetting before finalizing your purchase. Aside from inspecting the hull and outer surfaces, also examine the engine to ensure that the previous owner maintained the system with Evinrude XD 100 and other essential fluids.