Service parts for the Quiet Diesel 12500
Grouped by system, with how many of each the parts manual calls for.
Air intake
1 requiredFuel system
1 requiredOil system
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | Diesel |
|---|---|
| Frequency | 60.0 Hz |
| Voltage options | 120 V |
| Phase | Single |
| Rated current | 58.3 A |
| Dry weight | 290 kg |
| Sound level | 64.0 dBA |
Maintenance & consumables
for the Cummins/Onan Quiet Diesel| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Air Filter | 981-0139 | Amazon eBay | ||
| Fuel filter | Fuel Filter | 981-0627 | Amazon eBay | ||
| Oil filter | Oil Filter | 981-0246B | Amazon eBay | ||
| Battery | Clean & Check Battery & Connections | — | 50 hr | ||
| Spark plug | Replace Spark Plugs | — | 250 hr |
Common questions
What engine does the Cummins/Onan Quiet Diesel 12500 use?
The Cummins/Onan Quiet Diesel 12500 is powered by the Cummins/Onan Quiet Diesel engine.
What kind of fuel does the Cummins/Onan Quiet Diesel 12500 run on?
The Cummins/Onan Quiet Diesel 12500 runs on Diesel.
Which oil filter part number does the Cummins/Onan Quiet Diesel 12500 take?
The Cummins/Onan Quiet Diesel 12500 uses oil filter part number 981-0246B.
What fuel filter fits the Cummins/Onan Quiet Diesel 12500?
The Cummins/Onan Quiet Diesel 12500 uses fuel filter part number 981-0627.
What air filter does the Cummins/Onan Quiet Diesel 12500 use?
The Cummins/Onan Quiet Diesel 12500 uses air filter part number 981-0139.
Troubleshooting
6Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| FAILS TO CRANK | 1. Low battery. 2. Bad battery connection. 3. Blown fuse. | 1. Check battery fluid level. 2. Clean & tighten all battery & cable connections. 3. Replace fuse on control panel. |
| CRANKS SLOWLY | 1. Low battery. 2. Bad battery connection. 3. Incorrect oil viscosity. 4. Load connected. | 1. Check battery fluid level. 2. Clean & tighten all battery & cable connections. 3. Replace with recommended viscosity oil. 4. Disconnect load before starting. |
| CRANKS BUT WON’T START | 1. Fuel below generator pickup level in tank. 2. Fuel supply shutoff valve closed. 3. Carbon deposits on spark plug(s). 4. Low oil level. | 1. Add fuel. 2. Fully open fuel supply valve. 3. Remove spark plug(s) and replace. 4. Add oil. |
| EXHAUSTING BLACK SMOKE | 1. Dirty air filter. | Replace air filter. |
| UNIT RUNS THEN STOPS, OR STOPS WHEN DRIVING AROUND A CORNER | 1. Low fuel level. 2. Low oil level. 3. Excess oil. | 1. Add fuel. 2. Add oil. 3. Reduce engine oil level. |
| UNIT STARTS AND RUNS, THEN STOPS WHEN THE START SWITCH IS RELEASED | 1. Low fluid levels. | Check & bring all fluids up to the appropriate levels. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan Quiet Diesel 12500 troubleshooting guide (8 entries) →
Parts
19| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 981-0139 | Air Filter | 2 | Air filter | Amazon eBay |
| 981-0158C | Battery | 1 | Battery | Amazon eBay |
| 981-0164B | Battery | 1 | Battery | Amazon eBay |
| 981-0169 | Battery | 2 | Battery | Amazon eBay |
| 981-0238F | Air Filter | 4 | Air filter | Amazon eBay |
| 981-0246B | Oil Filter | 3 | Oil filter | Amazon eBay |
| 981-0503 | Spark Plug | 2 | Spark plug | Amazon eBay |
| 981-0518D | Oil Filter | 4 | Oil filter | Amazon eBay |
| 981-0607 | Fuel Filter | 1 | Fuel filter | Amazon eBay |
| 981-0621 | Battery | 1 | Battery | Amazon eBay |
| 981-0623 | Fuel Filter | 1 | Fuel filter | Amazon eBay |
| 981-0631B | Battery | 1 | Battery | Amazon eBay |
| 981-0633B | Battery | 1 | Battery | Amazon eBay |
| 981-0640 | Fuel Filter | 2 | Fuel filter | Amazon eBay |
| 983-0101B | Battery | 3 | Battery | Amazon eBay |
| 983-0201C | Battery | 3 | Battery | Amazon eBay |
| 983-0501C | Battery | 3 | Battery | Amazon eBay |
| 983-0600 | Battery | 1 | Battery | Amazon eBay |
| 981-0627 | Fuel Filter | 1 | Service part / kit | Amazon eBay |
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.