If you haven't gone green by using oars or an electric motor on your tender, you probably have either an outboard or a jet-drive boat. While we recommend following your engine manufacturer's maintenance regimen, we've found that tenders need special care because of their sometimes-sporadic usage schedules. Here are a few helpful tips to make sure getting started will rarely be a problem. The bigger, more sophisticated direct-injected two- and four-stroke engines are, for the most part, difficult for an owner to maintain properly. Keep them serviced by a manufacturer-approved dealer. But no matter what size outboard engine you have, it must be kept clean. And that means daily freshwater washdowns if the tender is brought aboard and stowed. If you leave it in the water, tilt the drive up and wipe down the cowling and all exposed parts. With saltwater operation, most engine manufacturers suggest you flush out the cooling system after each use. If circumstances do not allow this, make sure to do it as often as possible. This simple procedure is performed out of the water by hooking up the familiar "earmuff" devices or by direct hose input should your engine have one. Run the fresh water through the cooling system for about ten minutes at idle to ensure any salt deposits, sand, and debris are cleared. As with any outboard, you should always look for the telltale stream of cooling water. If the output of water is not as it should be, there may be a blockage. Snake a length of wire up the hose to help free things up. If this doesn't work, it is most likely the water pump impeller. As far as impeller maintenance, the "if it ain't broke don't fix it" adage works best. Even with heavy use, impellers usually have a two-year life before any problems arise. Keep in mind that some tenders often stir up sandy bottoms in far-flung anchorages-which can have an adverse effect. No matter what the horsepower, your outboard needs to have the correct oil. If you're running a two stroke, look for the TC-W3 tag on the container. Four-strokes have a FC-W designation. Make sure you do regular oil changes as per your engine manual. On smaller engines, and those with external gasoline tanks where mixing oil and gasoline is necessary, always do so in the proper ratio. For example, with Yamaha two-stroke outboards of 25 horsepower or less, a 100:1 pre-mix is required. The company offers its Ratio-Rite cup to ensure this critical proportion is precisely measured. Fouled, burnt, or eroded spark plugs will cause starting problems. With proper engine maintenance, getting 100 hours out of a spark plug is possible. It's easy to remove a plug using a deep spark-plug socket. Gap them per manufacturers' specs. Some identifying electrode-end conditions include eroded or whitish deposits (indicative of overheating), water-wet, or very clean, means there is water in the cylinder, and a heavy carbon deposit points to using the wrong oil or too much oil in the gasoline. If there is any doubt as to the condition of your plugs, swap them out for new ones. Spare plugs are inexpensive insurance-keep a few on hand. While keeping up with regular maintenance on jet-drive engines, including oil and filter changes, Bruce Woodfin, northeast distributor for Hamilton Jet, recommends a yearly application of Tri-Lux 33 anti-fouling paint to the jet, including up inside the intake. "The most important thing you should do is rinse out the jet with fresh water after you haul the tender," said Woodfin. A puddle of salt water can form inside the tailpipe and impeller race area and cause problems.