Generac GN-220 Engine Engine

Shared across brands: Generac, Magnum

• Start/Stop switch at Stop, engine continues to run.
  Cause: Defective Start/Stop switch
  Fix: Replace switch.
• Low Voltage Shutdown M04
• High Temperature Shutdown M02
• Engine starts, shuts down when Start/Stop switch is released.
  Cause: Engine oil is low.
  Fix: Check oil; add as needed.
• Engine won't crank.
  Cause: 15 amp fuse is blown.
  Fix: Replace 15 amp fuse.
• Engine cranks but won't start.
  Cause: Out of fuel.
  Fix: Replenish fuel.
• Overspeed Shutdown M03
  Fix: Do not attempt a manual adjustment to control engine speed.
• Low Oil Pressure Shutdown M01
  Fix: Check the engine oil level. If necessary, add oil to the FULL mark.
• Engine starts hard, runs rough, low full load power.
  Cause: 1. Air cleaner plugged or damaged. 2. Defective spark plug. 3. Loose spark plug boot.
  Fix: 1. Clean or replace as needed. 2. Clean, regap or replace plug. 3. Press boot on securely.
• No output from generator.
  Fix: Check circuit breaker. Reset to ON
• Engine starts hard, runs rough.
  Cause: Air cleaner plugged or damaged.
  Fix: Clean or replace as needed.
• W WARNING QA
• Stator windings are shorted to ground
  Fix: The Stator should be cleaned and dried. The Insulation resistance tests should then be repeated. If, after cleaning and drying, the Stator again falls the test, replace the Stator assembly.
• If the engine starts but the Stepper Motor does not move, and shutdown occurs after several seconds
  Cause: Broken or shorted Power Supply winding (Wires PS1 and PS2)
• If the engine shuts down but speed did NOT exceed 4500 rpm
  Cause: One of the main windings (Power Phase 1 or 2) Is open

Compiled from service & troubleshooting documentation across every generator set that uses the Generac GN-220.

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.