Kohler CH740 4-Cycle Engine Engine

• Gas fuel leaks can cause an explosion.
  Fix: Check the LP vapor gas or natural gas fuel system for leakage by using a soap and water solution with the fuel system test pressurized to 6–8 ounces per square inch (10–14 inches water column). Do not use a soap solution containing either ammonia or chlorine because both prevent bubble formation. A successful test depends on the ability of the solution to bubble.
• Undervoltage shutdown UU
  Cause: Shutdown occurs if the voltage falls below 80% of the nominal system voltage for more than 10 seconds.
  Fix: Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues.
• Underfrequency shutdown UF
  Cause: Shutdown occurs if the governed frequency falls below 54 Hz for more than 5 seconds. Shutdown also occurs if the governed frequency falls below 56.5 Hz for more than 60 seconds. This function becomes active 10 seconds after engine start. (10 second inhibit).
  Fix: Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues.
• The generator set does not crank.
  Cause: Battery weak or dead, Battery charger fuse blown, Battery connections reversed or poor, Controller fuse (F3) blown, Relay interface board fuse (F2) blown
  Fix: Check power to the battery charger. Recharge or replace the battery. Replace the fuse. Contact an authorized distributor/dealer for service if fuse blows repeatedly. Check the connections. Replace the fuse. Contact an authorized distributor/dealer for service if fuse blows repeatedly.
• The generator set also shuts down on OC if no engine rotation is sensed during cranking. Shuts down 3 seconds after the fault is detected. Locked rotor
• Stops suddenly
  Cause: Fault shutdown
  Fix: Check for a fault shutdown code on the controller’s LED display. Correct the fault and then move the generator set master switch to OFF/RESET to reset the controller.
• Stator problem
  Fix: Check voltage and continuity.
• Shutdown occurs when the governed frequency falls 1 Hz below the system’s frequency setpoint for more than 1 second. UF
  Fix: Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues.
• Shutdown occurs when the governed frequency exceeds 110% of the system’s frequency setpoint for more than 1 second. This protective becomes active 30 seconds after engine start. OF
  Fix: Contact an authorized distributor/dealer for service if problem continues.
• Shutdown occurs if the voltage falls below 80% of the voltage regulator setpoint for more than 1 second. This protective becomes active 30 seconds after engine start. UU
  Fix: Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service if problem continues.
• Shutdown occurs if the voltage exceeds 120% of the voltage regulator setpoint for more than 1 second. OU
  Fix: Contact an authorized distributor/dealer for service if problem continues.
• Shutdown occurs if the engine speed exceeds 115% of the normal running speed for more than 1 second. OS
  Fix: Contact an authorized distributor/dealer for service if problem continues.
• Shutdown occurs if the engine coolant temperature exceeds the maximum temperature for more than 5 seconds. This protective becomes active after the engine reaches the crank disconnect speed. HE
  Fix: Check for blocked air inlets and exhaust outlets.
• Shutdown occurs if a low oil pressure condition exists 7 seconds after the engine has reached crank disconnect speed. LOP
  Cause: Note: The low oil pressure shutdown does not protect against low oil level. Check the oil level at the engine. Check for leaks in the lubrication system.
  Fix: Check the oil level and add oil if the level is low.
• Shutdown occurs after 3 unsuccessful starting attempts. The crank cycle is set for three starting attempts of 15 seconds cranking and 15 seconds rest. The generator set also shuts down after 1 crank attempt if no speed signal is sensed. Shuts down 1 second after the fault is detected. OC
  Cause: Check the fuel supply, spark plug, and battery. Check for loose connections.
  Fix: Contact an authorized distributor/dealer for service if problem continues.

Compiled from service & troubleshooting documentation across every generator set that uses the Kohler CH740 4-Cycle.

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