Specifications
| Fuel | natural gas or propane |
|---|---|
| Frequency | 60.0 Hz |
| Controller | DC-RET Digital, Kohler-DC-RET Digital |
| Oil capacity | 1.9 L |
Maintenance & consumables
for the Kohler CH740| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | — | 300 hr | find | ||
| Fuel filter | — | 52 hr | find | ||
| Oil filter | Pack first: complete service kit comprising air filter, spark plugs and oil filter. | ×1 | — | 200 hr | find |
| Belt | — | 12 hr | find | ||
| Coolant | — | 52 hr | |||
| Oil | 2.7 L | — | 100 hr |
Common questions
What engine does the Kohler 12RES use?
The Kohler 12RES is powered by the Kohler CH740 engine.
What fuel does the Kohler 12RES use?
The Kohler 12RES runs on natural gas or propane.
What is the oil capacity of the Kohler 12RES?
The Kohler CH740 engine in the Kohler 12RES has an oil capacity of 1.9 liters.
Troubleshooting
10Fault codes
| Code | Meaning |
|---|---|
| High engine temperature | Engine runtime, hours |
| Low battery voltage | Crank cycle status |
| Overcrank | Remote two-wire start/stop capability |
| Overfrequency | Digital voltage regulation: ±1.5% RMS no-load to full-load |
| Overspeed | Automatic start for programmed cranking cycle |
| Underfrequency | Master control switch mounted on the junction box: Run/Off-Reset/Auto |
| Undervoltage | Upgradeable application software |
Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Severe electrical equipment damage. | Welding the generator set. | Never weld components of the generator set without first disconnecting the battery, controller wiring harness, and engine electronic control module (ECM). |
| Accidental starting | Disconnect the battery cables before working on the generator set. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. | |
| Battery short circuit | Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. Never connect the negative (--) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
128| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 12 050 01-S | Oil Filter | 8 | Oil filter | PartsGeek kuduparts $32.00 |
| 12 132 02-S | Spark plug | 2 | Spark plug | PartsGeek |
| 24 029 124-S | Adapter, Oil Filter | 1 | Oil filter | PartsGeek |
| 24 032 19-S | Seal, oil front | 1 | Seal | PartsGeek |
| 24 050 01-S | Filter, breather | 8 | Filter | PartsGeek |
| 24 083 08-S | Element, air filter | 1 | Air filter | PartsGeek |
| 24 083 09-S | Element, air filter | 1 | Air filter element | PartsGeek |
| 24 136 08-S | Nipple, Oil Filter | 1 | Oil filter | PartsGeek |
| 24 153 01-S | O-ring | 1 | Seal | PartsGeek |
| 24 153 08-S | O-ring | 1 | Seal | PartsGeek |
| 24 153 21-S | O-ring, oil cooler | 1 | Seal | PartsGeek |
| 24 153 33-S | Seal, Oil Pump Cover | 1 | Seal | PartsGeek |
| 24 153 34-S | O-Ring, Oil Pick-Up | 1 | Seal | PartsGeek |
| 24 381 13-S | Pick-Up Assembly, Oil | 1 | Pump | PartsGeek |
| 24 393 51-S | Kit, oil pump assembly (includes items 12, 13) | 1 | Pump | PartsGeek |
| 24 393 70-S | Pump Assembly, Oil | 1 | Pump | PartsGeek |
| 24 590 01-A | Oil Cooler, 14RCA/L | Oil cooler | PartsGeek | |
| 241927 | Kit, speed sensor | 1 | Sensor | PartsGeek |
| 25 032 06-S | Seal, oil | 1 | Seal | PartsGeek |
| 25 099 26-S | Switch, oil pressure | 1 | Sensor | PartsGeek |
| 25 132 14-S | Spark plug (RFI) | 2 | Spark plug | PartsGeek |
| 25 435 06-S | Kit, starter solenoid | 1 | Kit | PartsGeek |
| 269373 | Alternator Assembly | 5 | Alternator | PartsGeek |
| 358072 | 3/8"-16 UNC-2A THD Thrubolt | 1 | Thrubolt | PartsGeek |
| 52 099 08-S | Switch, oil pressure | 1 | Sensor | PartsGeek |
| 62 590 01 | Oil Cooler, 20RCA/L | Oil cooler | PartsGeek | |
| ADV-6823-A | Air Filter, Spark Plug Location | 1 | Air filter | PartsGeek |
| BKR-8YU11 | Spark Plug, CH20/CH740 | 4 | Spark plug | eBay PartsGeek |
| GM101737 | Lifting bars | 4 | Lifting bar | PartsGeek |
| GM103159 | Oil, Synthetic Quart 5W30 | 3 | Fluid | Amazon eBay $155.00 PartsGeek |
| GM103743 | Emergency Stop Switch (optional) | 1 | Emergency stop switch | PartsGeek |
| GM111084 | Shutdown Switch | 1 | Shutdown switch | PartsGeek |
| GM28823 | Sensor, temperature (oil) | 1 | Sensor | PartsGeek |
| GM29253-GA2 | Controller Wiring Diagram | 1 | Controller wiring diagram | PartsGeek |
| GM29358-B | Point-to-Point Wiring Diagram, Single Phase | 1 | Point-to-point wiring diagram | PartsGeek |
| GM51559 | 3/8"-16 UNC-2A THD Thrubolt | 1 | Thrubolt | PartsGeek |
| GM90304 | Revised RDC2 Controller | 1 | Display | PartsGeek |
| RSP-FT-02-US-91 | Pack first: complete service kit comprising air filter, air pre filter, spark plugs and oil filter. | Air filter | PartsGeek | |
| RSP-FT-04-US-91 | Pack first: complete service kit comprising air filter, air pre filter, spark plugs and oil filter. | Air filter | PartsGeek | |
| 12RES | KOHLER 12RES generator | Service part / kit | PartsGeek | |
| 223316 | Fuse, 10 A, 250 V | 5 | Service part / kit | PartsGeek |
| 230578 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek FridayParts $24.68 | |
| 24 083 02-S | Pre-cleaner | 8 | Service part / kit | PartsGeek |
| 24 083 05-S | Pre-cleaner | 8 | Service part / kit | PartsGeek |
| 24 594 66-S | Cooler, Oil & Diverter Assembly | 1 | Service part / kit | PartsGeek |
| 292937 | Fuse, 20 A, 250 V | 5 | Service part / kit | PartsGeek |
| F-228605 | Kit, voltage regulator | 1 | Service part / kit | PartsGeek |
| GM10064 | PCB assembly (relay controller) | 1 | Service part / kit | PartsGeek |
| GM29671 | PCB assy, relay board 12V | 1 | Service part / kit | PartsGeek |
| ML25KZAG | Kohler 25 HP CH740 Gasoline Engine | 1 | Service part / kit | PartsGeek |
| SBECBA24 | Bell Alarm | 1 | Service part / kit | PartsGeek |
| SBECDMR24 | Alarm Contact Relay | 1 | Service part / kit | PartsGeek |
| X-125-22 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-23 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-24 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-25 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-26 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-27 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-28 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-29 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-3 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-30 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-31 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-32 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-33 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-34 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-35 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-36 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-38 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-39 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-40 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-43 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-44 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-125-5 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-15 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-17 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-18 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-19 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-2 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-20 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-21 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-22 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-23 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-129-24 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-10 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-11 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-12 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-14 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-16 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-17 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-18 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-2 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-20 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-21 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-25 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-6 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-7 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-8 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-465-9 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-11 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-12 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-2 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-3 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-4 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-5 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6024-8 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-1 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-10 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-11 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-12 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-13 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-14 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-16 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-17 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-18 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-19 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-2 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-20 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-21 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-22 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-25 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-3 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-4 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-5 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-6 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-7 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-8 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek | |
| X-6238-9 | Hex Head Bolt (Grade 5) | Service part / kit | PartsGeek |
Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
| Null | 25% | 93.0 | |
| Null | 50% | 124.0 | |
| Null | 75% | 163.0 | |
| Null | 100% | 193.0 |
Available documents
Spec sheet (Kohler)Installation manual — tp6397 (Kohler)Installation manual — tp6516 (Kohler)Installation manual — tp6793 (Kohler)Installation manual — tt1428 (Kohler)Installation manual — tt1445 (Kohler)Reference (Kohler)Owner's manual — tp6398 (Kohler)Owner's manual — tp6517 (Kohler)Parts manual (Kohler)Service manual — tp6196 (Kohler)