Kohler L654 Engine

How to read your Kohler engine serial & model number →

• Unit Will Not Shut Down with Switch in Off Position
  Cause: No ground connection to engine magneto (Section 5). Faulty “CR” relay contacts (Section 5).
• Unit Will Not Crank with Switch in Test Position
  Cause: Weak or dead battery. Reversed or poor battery connections — must be negative ground (Section 2). Faulty “C” cranking solenoid (Section 5). Faulty starter motor. Open harness connections (Section 5). Blown fuse (Section 5). Open jumper, terminal strip P to B+ (Section 5). Open jumper, terminal strip 50 to 51 (Section 5). Faulty “2CR” relay contacts. Faulty switch.
• Unit Stops Suddenly
  Cause: No fuel. No spark (Section 11). Improper cooling (high temperature cutout) (Section 10). improper lubrication (low oil pressure cutout) (Section 1). Valve problems (Engine Manual, ES-652). Set overloaded (Section 1). Emergency stop circuit energized.
• Unit Starts but Shuts Down Within 30 Seconds
  Cause: Low engine oil pressure (Section 1). Faulty engine temperature sensor (Section 10). High temperature cutouts (Section 10). Two amp fuse blown (Section 5). No AC output-voltage (Section 7). Defective “1CR” or “4CR” relay (Section 5).
• Unit Skips or Misfires
  Cause: Fuel mixture wrong (Section 9). Poor ignition (Section 11). Valve problems (Engine Manual, ES-652).
• Unit Runs-No AC Output (Shut-down after 30 Seconds)
  Cause: Open in voltage build-up circuit (Section 7). Faulty voltage regulator (Section 7). Sticky generator brushes (Section 7). Faulty generator rotor (Section 7). Faulty or misconnected generator stator (Section 7).
• Unit Overheats
  Cause: Improper cooling (Section 10). Set overloaded (Section 1). improper lubrication (Section 1). Fuel mixture wrong (Section 9). Valve problems (Engine Manual, ES-652). Poor ignition (Section 11).
• Unit Operates Erratically
  Cause: Improper fuel (Section 1). Fuel mixture wrong (Section 9). Poor ignition (Section 11). Faulty governor (Section 9). Full fuel collection tank (Section 9).
• Unit Lacks Power
  Cause: Improper fuel (Section 1). Fuel mixture wrong (Section 9). Poor ignition (Section 11). Improper cooling (Section 10). Poor compression (Engine Manual, ES-652). Valve problems (Engine Manual, ES-652). Carbon build-up (Engine Manual, ES-652). Set overloaded (Section 1).
• Unit Knocks or Pings
  Cause: Improper fuel (Section 1). Fuel mixture wrong (Section 9). Poor ignition (Section 11). Improper cooling (Section 10). Carbon build-up (Engine Manual, ES-652). Set overloaded (Section 1).
• Unit is Hard Starting
  Cause: Improper fuel (Section 1). Fuel mixture wrong (Section 9). Improper cooling (Section 10). Poor compression (Engine Manual, ES-652). Valve problems (Engine Manual, ES-652). Choke out of adjustment (Section 9). Faulty ignition system (magneto, spark plugs, breaker points) (Engine Manual, ES-652).
• Unit Cranks but Will Not Start
  Cause: No fuel. No spark (Section 11). Open or ground in harness assembly (Section 5). Faulty “CR” relay. Poor compression (Engine Manual, ES-652). Valve problems (Engine Manual, ES-652). Defective choke (Engine Manual, ES-652).
• Unit Backfires
  Cause: Fuel mixture wrong (Section 9). Poor ignition (Section 11). Valve problems (Engine Manual, ES-652).

Compiled from service & troubleshooting documentation across every generator set that uses the Kohler L654.

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