Service parts for the NP66G
Grouped by system, with how many of each the parts manual calls for.
Air intake
1 requiredFuel system
1 requiredOil system
1 requiredBelts
1 requiredIgnition
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
| Fuel | gasoline |
|---|---|
| Frequency | 60.0 Hz |
| Voltage options | 120 V, 240 V |
| Phase | 1 |
| Rated current | 55 A |
Filters & service parts
model family| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | 73123 | 100 hr | Amazon $138.98 eBay $25.00 | ||
| Fuel filter | 75213 | 100 hr | Amazon eBay $56.99 FridayParts $56.99 | ||
| Oil filter | 70185 | 100 hr | Amazon $28.95 eBay $18.99 KuduParts $11.00 | ||
| Battery | 12 volts d-c | — | |||
| Belt | 75216 | Amazon eBay | |||
| Oil | SAE 10W-30 API Service SF | — | 50 hr | ||
| Spark plug | 72347 | 100 hr | Amazon $7.19 eBay $9.99 |
Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.
Common questions
What kind of fuel does the Generac NP66G run on?
The Generac NP66G runs on gasoline.
What oil filter fits the Generac NP66G?
The Generac NP66G uses oil filter part number 70185.
Which fuel filter part number does the Generac NP66G take?
The Generac NP66G uses fuel filter part number 75213.
Which air filter part number does the Generac NP66G take?
The Generac NP66G uses air filter part number 73123.
Troubleshooting
5Symptoms & remedies
| Symptom | Cause | Remedy |
|---|---|---|
| Engine Won't Crank. | 1. 15 amp fuse biown. 2. Loose, corroded or defective battery cable(s). 3. Battery is discharged or defective. 4. Defective starter contacior. 5. Defective starter motor. 6. Defective control relay (CR1). | 1. Repiace biown fuse. 2. Tighten, clean or replace, as necessary. 3. Recharge or repiace battery. 4. Replace starter contactor. 5. Replace starter motor. 6. Replace control relay. |
| Engine Cranks, won't Start. | 1. Out of fuel. 2. Fuel shutoff valve(s) in fuel supply line are closed. 3. Fuel pump not operating. 4. Automatic choke not operating properly. 5. Engine is flooded. 6. Fuel filter clogged. 7. Defective Control Relay (CR2). 8. Engine spark plugs defective. 9. Bad ignition magneto on engine. 10. Bad carburetor. 11. Dirty air cleaner. | 1. Refill tuel tank. 2. Open fuel shutoff valve(s). 3. Repair or replace bad pump. 4. Repair, replace or adjust. 5. Wait 5-10 minutes, try again. 6. Replace if clogged. 7. Replace bad relay CR2 8. Clean, regap or replace as necessary. 9. Replace if defective. 10. Adjust, repair or repiace. 11. Clean or replace as needed. |
| Engine Starts Hard, Runs Rough | 1. Dirty engine air cleaner. 2. Automatic choke is sticking. 3. Defective spark plugs. 4. Defective ignition magneto. 5. Water in fuel. | 1. Clean or replace as needed. 2. Free choke linkage as needed: 3. Clean, regap or replace. 4. Replace if bad. 5. Drain tank and refill. |
| Engine Starts, then Shuts Down | 1. Engine oil level is low. 2. Bad control relay (CR1) 3. Bad low oil pressure switch. 4. Bad control relay (CR2) | 1. Add oil as needed. 2. Replace if bad. 3. Replace if bad. 4. Replace bad relay CR2 |
| No a-c Output Voltage | 1. Main breaker(s) open. 2. Transfer switch (if so equipped) is set to wrong position. 3. Failure in vehicle electrical system. 4. Generator component failure. | 1. Close main breaker(s). 2. Reset transfer switch. 3. See vehicle manual. 4. Contact an authorized service facility. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Repair guides
6- RECONNECTION FOR DUAL VOLTAGE OUTPUT (CONTINUED):
- STARTING THE GENERATOR:
- STOPPING THE GENERATOR:
- RECONNECTION FOR DUAL VOLTAGE OUTPUT (CONTINUED):
- STARTING THE GENERATOR:
- STOPPING THE GENERATOR:
Step-by-step procedures compiled from the Generac service manual for this model.
Parts
44model family| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 47662-AW | 5/15" dia. x 4-1/2" Hose | 1 | Hose | Amazon eBay |
| 47662-BC | 3/8" x 10-1/2" Hose | 1 | Hose | Amazon eBay |
| 47662-BF | 5/16" dia. Hose | 1 | Hose | Amazon eBay |
| 47662-T | 4-1/2" long Fuel Hose | 1 | Hose | Amazon Amazon eBay eBay |
| 66480 | Air Cleaner Gasket | 1 | Gasket | Amazon $69.99 eBay |
| 67805 | OIL SEAL-30 DIAMETER | 1 | Seal | Amazon eBay |
| 67866 | O-RING | 1 | Seal | Amazon $51.95 eBay |
| 67871 | O-RING, CAP | 1 | Seal | Amazon eBay $9.44 |
| 67895 | GASKET, INTAKE MANIFOLD | 2 | Gasket | Amazon $9.99 eBay |
| 67897 | Exhaust Gasket | 2 | Gasket | Amazon $10.69 eBay |
| 67920 | Valve Cover Gasket | 2 | Gasket | Amazon eBay $17.67 |
| 67924 | OIL SEAL-35 DIAMETER | 1 | Seal | Amazon eBay |
| 68548 | Oil Pad Gasket | 1 | Gasket | Amazon $29.99 eBay |
| 68554 | Governor Shaft Seal | 1 | Seal | Amazon $56.85 eBay |
| 68573 | O-RING, OIL PUMP | 1 | Seal | Amazon $54.99 eBay FridayParts $79.99 |
| 69332 | Cylinder Head Gasket | 2 | Gasket | Amazon eBay |
| 69336 | GASKET, OIL SUMP | 1 | Gasket | Amazon eBay |
| 69341 | Foam Pre-cleaner | 1 | Air filter | Amazon eBay |
| 69379 | Carburetor Mounting Gasket | 2 | Gasket | Amazon eBay |
| 70122 | Valve Stem Seal | 2 | Seal | Amazon $17.95 eBay |
| 70169 | Sealing Washer | 4 | Seal | Amazon eBay |
| 70185 | FILTER, OIL | 1 | Oil filter | Amazon $28.95 eBay $18.99 KuduParts $11.00 |
| 70506 | O-RING, OIL GALLEY | 1 | Seal | Amazon $41.03 eBay |
| 70547 | OIL PUMP ASSEMBLY | 1 | Pump | Amazon $67.99 eBay |
| 72315 | GASKET, BREATHER | 1 | Gasket | Amazon eBay |
| 72347 | SPARK PLUG-CHAMPION R12YC | 1 | Spark plug | Amazon $7.19 eBay $9.99 |
| 72383 | Collector Pan Gasket | 2 | Gasket | Amazon $35.90 eBay |
| 73123 | Air Filter | 1 | Air filter | Amazon $138.98 eBay $25.00 |
| 74952 | Fuel line -- 5/16" ID | 1 | Hose | Amazon eBay |
| 75213 | Fuel filter | 1 | Fuel filter | Amazon eBay $56.99 FridayParts $56.99 |
| 75216 | 40" Poly Vinyl 4L Belt | 1 | Belt | Amazon eBay |
| 75253 | Washer Valve Cover Seal | 4 | Seal | Amazon $229.50 eBay |
| 75258 | Engine Gasket Kit | 1 | Gasket | Amazon eBay $69.99 |
| 75262 | SEAL, BREATHER SCREW | 1 | Seal | Amazon eBay |
| 75263 | SEAL, BREATHER SCREW | 1 | Seal | Amazon eBay |
| 75281 | High Temperature Switch | 1 | Sensor | Amazon eBay |
| 75711 | O-ring Adaptor | 1 | Seal | Amazon eBay |
| 75712 | O-ring Drain | 1 | Seal | Amazon $84.99 eBay |
| 77643 | Exhaust Outlet Gasket | 2 | Gasket | Amazon $15.55 eBay $13.87 |
| 77663 | Fuel pump | 1 | Pump | Amazon eBay $25.50 |
| 77667 | Oil Pressure Switch | 1 | Sensor | Amazon $9.99 eBay $9.99 |
| 70535 | Oil Screen | 1 | Service part / kit | Amazon eBay |
| 75252 | Carburetor Overhaul Kit | 1 | Service part / kit | Amazon eBay |
| 75271 | Valve Overhaul Kit | 1 | Service part / kit | Amazon eBay |
Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Available documents
Reference — Y78800 (Generac)Reference — Y78800 (Generac)Owner's manual — NP52G (Generac)Parts manual — Chart4 (Generac)