Changing the oil in a car is easy. On a boat, the engine is generally buried in the bilge and draining is awkward or impossible. Even outboard-powered boats (like our test boat, a 34-foot-long, 16-foot-wide catamaran) can be a oil-changing challenge. For these boats, changing the oil by sucking it through the dipstick hole is an effective solution.
When our home-built oil-changing system-a hand-powered vacuum pump and two one-quart bottles-that we had used for years to change the oil in our test boats twin 9.9-horsepower outboards, finally wore out, we decided to try the 2.9-quart West Marine Oil Changer. We still liked the idea of suction rather than pumping and wanted a unit that would contain the oil for transport to a recycling center.
Operating the West Marine Oil Changer is dead simple. Run the engine for a few minutes to warm the oil; warm oil will drain easier and the pumping is faster (45 seconds per quart at 120 degrees, or 140 seconds at 70 degrees). Insert the pickup hose in the dipstick hole, working it to the bottom of the sump, and then pump the handle 10 to 12 times to build a vacuum; oil removal begins immediately as there is no valve. To empty the Oil Changer, simply remove the hose, insert the transport plug, take it to a recycling center, and dump.
The Oil Changer ($55 at West Marine) does have downsides. The hose is coiled in the packaging, so allow time for it to straighten. The transport plug is not very secure, but it is adequate as long as it remains upright. Once the unit has recovered more than 1.5 quarts, there is a ball check that will prevent further movement of the pump handle.
Bottom line: After eight oil changes, testers are pleased with its performance and value. We Recommend it for use with small engines. Diesel owners may prefer using the 3.5-gallon-capacity, electric Jabsco Oil Changer we tested in 2007 (see PS January 2007 online).