How to Test a Boat Stator

by Will Charpentier

When your outboard motor refuses to start, remember that with gasoline engines, more problems are caused by the electrical and electronics systems than by the fuel or fuel distribution systems. Once you eliminate the possibility of a dead battery, broken wires or bad spark plugs, look at the stator, located on top of the block where the condensers and points are found. While some tests require the expensive equipment found only at the dealership, testing the stator requires only a $15 meter found at most hardware stores.

Disconnect the battery cables from the battery. You won't need an electrical flow for this test.

Try to wiggle the stator plate. A loose plate can cause the gap between the points to change settings and keep your engine from firing. Tighten it with a wrench, if necessary.

Look up the range of resistance for your stator in your motor operator's manual.

Turn the selector on your multimeter to the "Ohms" setting. The volts range is marked with the capital letter "V," the amps range is marked with a capital "A." The ohms range is marked with the Greek letter omega, shaped somewhat like an upside-down "U."

Set the one of the multimeter's probes against one of the connections of one of the blue stator wires and the other multimeter probe against the remaining connection. Read the number of ohms on the multimeter and compare it to the range in the operators' manual. If the resistance, measured in ohms, is within that range when tested, your stator isn't the problem. If the resistance is quite a bit higher (called "infinite resistance), the stator requires replacement.

Items you will need

  • Wrench
  • Motor operators' manual
  • Multimeter

Warning

  • Always view electricity with a healthy respect and a degree of skepticism. Remember that it only takes one-tenth amp of current to seriously injure or kill a person.

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.