• Stator/Rotor Output
  • Shorted or Grounded Stator
  • Voltage Regulator Function




To Check Stator/Rotor Output

  1. Disconnect the stator plug
  2. Start bike
  3. Set multimeter to VAC
  4. Read across the stator plug (one probe in each hole)
  5. Have someone rev the bike up to 2000-3000 RPM
  6. Stator/Rotor output should be 16-20 VAC per 1000 RPM

On a three-phase system there are three separate windings hooked end to end. You need to test the voltage on each set of windings. The plug has three pins. First take a voltage reading between pin one and pint two. Then pin one and pin three. And finally pin two and pin three. This will test all three windings. All three should read the same voltage at the same RPM.

To Check For a Shorted or Grounded Stator

  1. Set multimeter to “ohms”
  2. Read across the stator plug
  3. Resistance should be 0.2-0.3 ohms
  4. Now check each stator pin to ground
  5. Should have no continuity
  6. Reconnect stator plug

To Check Voltage Regulator Function

Regulator Ground Test:  Insure the regulator body is grounded or grounding wire is fasted tight to a good ground (you should verify this by checking continuity from regulator body to chassis ground). Check ground before you do the following tests below.

  1. Set multimeter to VDC
  2. Check battery voltage…12.5-13.0 VDC (if the battery isn’t fully charged, this test is useless)
  3. Start bike
  4. Hold the red lead of the multimeter to the positive post of the battery and the black lead to the negative post.
  5. Increase engine RPM to at least 2000 RPM
  6. Multimeter will show regulator charging rate which should be 14.0-14.7 VDC. A brand new fully charged battery will sometimes only indicate 14.0 VDC. Anything above 14.7 VDC is cooking the battery.