The Generac GN-190 or GN-220 (see NOTE 2) is an engine. It powers generator sets from Generac, including the NP-30G.
Also known as: Generac GN-190 or GN-220 (see NOTE 2)
Part of the Generac GN-190 engine family — 4 variants share parts & fitment.
Compiled from service & troubleshooting documentation across every generator set that uses the Generac GN-190 or GN-220 (see NOTE 2).
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Engine oil level | Check | 8 hr | At least every eight hours of operation, or before each use. Fill to dipstick FULL mark only. | |
| Air cleaner paper filter | Clean | 25 hr | 12 mo | or once each year, whichever comes first; replace if extremely dirty |
| Air cleaner paper filter | Replace | 25 hr | 12 mo | Every 25 hours or once each year, whichever comes first |
| Paper air filter | Clean | 25 hr | 12 mo | Once every 25 operating hours or once each year, whichever comes first; replace if too dirty |
| Engine oil | Change | 50 hr | First service — Thereafter, every 50 operating hours | |
| Oil filter | Change | 50 hr | First service — Thereafter, every 50 operating hours | |
| Oil filter | Replace | 50 hr | First service — Replace after the first 8 hours of operation, then every 50 operating hours | |
| Valve clearance | Adjust | 50 hr | First service — After the first 50 hours of operation | |
| Air intake screen | Clean | 100 hr | Clean more often if necessary | |
| Engine spark plug | Clean | 100 hr | Clean or replace and set gap to 0.030 inch (0.76mm) every 100 hours | |
| Fuel filter | Replace | 100 hr | 12 mo | or once each year, whichever occurs first |
| Spark arrestor | Clean | 100 hr | Inspect and clean every 100 hours of operation; replace if torn, perforated or damaged | |
| Spark plug | Clean | 100 hr | Clean or replace and set gap to 0.030 inch (0.76mm) | |
| Spark plug gap | Adjust | 100 hr | Reset to 0.030 inch (0.76mm) | |
| Battery | Test | 6 mo | Every six months have state of charge and condition checked with a battery hydrometer | |
| Battery state of charge and condition | Test | 6 mo | Have checked with an automotive type battery hydrometer |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Clearance | Carburetor throttle lever stop tab to stop block gap | 0.003 | inch | |
| Clearance | Crankshaft end play (allowable) | 0.006-0.023 | inch (0.14-0.60mm) | |
| Clearance | Oil pump tip clearance | 0.0000-0.0010 design / 0.004 wear limit | inch (0.000-0.025mm) | measured on shaft in oil sump |
| Clearance | Oil ring end gap | 0.015-0.055 design / 0.062 wear limit | inch | ring pushed down 2.75 inch |
| Clearance | Piston ring-to-groove side clearance | 0.0004-0.0014 | inch (0.012-0.034mm) | |
| Clearance | Second ring end gap | 0.006-0.016 design / 0.024 wear limit | inch | ring pushed down 2.75 inch |
| Clearance | Top ring end gap | 0.005-0.016 design / 0.024 wear limit | inch (0.15-0.40mm) | ring pushed down 2.75 inch (70mm) |
| Gap | Gap between throttle lever stop tab and carburetor stop block | 0.003 | inch (0.08-0.5mm) | |
| Gap | Spark plug gap | 0.030 | inch (0.8mm) | |
| Gap | Throttle lever stop tab to carburetor stop block gap | 0.003 | inch (0.08-0.5mm) | |
| Gap | Throttle linkage gap between stop tab and stop block | 0.003 | inch (0.08-0.5mm) | throttle lever rotated counterclockwise as engine coasts to a stop |
| Gap | Throttle linkage stop tab to stop block gap | 0.003 | inch | |
| Other | Carburetor high altitude jetting | 5000 | feet | altitudes in excess of 5000 feet; consult Authorized Service Facility |
| Other | Ignition timing | 29 degrees BTDC (at higher speeds); 15-18 degrees BTDC at cranking speeds | degrees BTDC | |
| Other | Minimum acceptable Stator insulation resistance | rated volts/1000 + 1 | megohm | |
| Other | Standard cylinder bore diameter | 2.7560-2.7570 (GN-190) / 2.953-2.954 (GN-220) | inches | |
| Other | Valve seat width | 0.034-0.044 design / 0.064 wear limit | inch (0.87-1.13mm) | grind seats to 45 deg, 0.040 inch width |
| Pressure | Engine compression pressure | 60 nominal / 55 minimum | psi | cold engine while cranking |
| Pressure | Engine compression pressure (while cranking, cold engine) | 55 | psi | minimum allowable |
| Pressure | Engine compression pressure (while cranking, cold engine) | 60 | psi | nominal |
| Pressure | Engine compression pressure, minimum allowable | 55 | psi | while cranking, cold engine |
| Pressure | Engine compression pressure, nominal | 60 | psi | while cranking, cold engine |
| Pressure | Fuel pump outlet pressure | 2.0 to 3.5 | psi | at zero delivery |
| Pressure | Fuel pump pressure at zero delivery | 2.0 to 3.5 | psi | |
| Pressure | LP gas inlet pressure to lockoff solenoid / secondary regulator | 11 | inches water column | |
| Pressure | LP gas inlet pressure to lockoff solenoid / secondary regulator | 11 (do not exceed 14) | inches water column | |
| Pressure | LP gas pressure at inlet to fuel lockoff solenoid and secondary regulator | 11 | inches of water column | optimum; do NOT exceed 14 inches water column |
| Pressure | Low oil pressure switch actuation | 5 | psi | |
| Pressure | Low oil pressure switch set point | 5 | psi | |
| Pressure | Oil pressure relief valve opening | 30 | psi (approx.) | |
| Pressure | Oil pressure relief valve opening pressure | approximately 30 | psi | |
| Resistance | Fuel pump coil | 0.75 to 1.00 | ohm | nominal |
| Resistance | Fuel pump coil nominal resistance | 0.75 to 1.00 | ohm | |
| Resistance | Genistor COM to G1/G2/G3/G4 | 20-60 | Ohms | |
| Resistance | Ignition coil primary | 0.5 to 1.5 | ohm | |
| Resistance | Ignition coil primary resistance | 0.5 to 1.5 | ohms | |
| Resistance | Ignition coil secondary | 16,000-17,000 | ohm | |
| Resistance | Ignition coil secondary | 16000-17000 | ohm | |
| Resistance | Ignition coil secondary resistance | 16,000-17,000 | ohms (16.0-17.0 k-Ohms) | |
| Resistance | Minimum acceptable stator insulation resistance | (rated volts / 1000) + 1 | megohms | e.g. 120 VAC rated = 1.12 megohms |
| Resistance | Stator Battery Charge Winding (66 to 55 / 77 to 55) | 0.037-0.042 | ohm | |
| Resistance | Stator Power Phase Windings (AC1/AC2/SL1/SL2 to lead 11) | 0.30 to 0.42 | ohm | |
| Resistance | Stator Power Supply Winding (PS1 to PS2) | 0.35-0.44 | ohm | |
| Resistance | Stator Timing Winding (TIM1 to TIM2) | 0.35-0.44 | ohm | |
| Resistance | Stator battery charge winding (lead 55 to 77) | 0.037-0.042 | ohm | |
| Resistance | Stator battery charge windings (66 to 55; 77 to 55) | 0.037-0.042 | ohm | |
| Resistance | Stator power phase windings (AC1, AC2, SL1, SL2 to lead 11) | 0.30 to 0.42 | ohm | |
| Resistance | Stator power phase windings (Lead AC1/AC2/SL1/SL2 to 11) | 0.30 to 0.42 | ohm | |
| Resistance | Stator power supply winding (PS1 to PS2) | 0.35 to 0.44 | ohm | |
| Resistance | Stator timing winding (TIM1 to TIM2) | 0.35 to 0.44 | ohm | |
| Resistance | Stepper motor winding (RED to ORANGE/YELLOW/BROWN/BLACK) | 19-21 | ohm | |
| Resistance | Stepper motor winding resistance | 19-21 | ohms | RED pin to ORANGE/YELLOW/BROWN/BLACK pins |
| Resistance | Stepper motor windings (RED to ORANGE/YELLOW/BROWN/BLACK) | 19-21 | ohm | |
| Speed | Engine operating speed (variable) | 2520 to 4050 | rpm | corresponds to stator output 336-540 Hz |
| Speed | Engine operating speed range | 2300-3910 | rpm | varies with load and load voltage |
| Speed | Engine overspeed shutdown | 4500 | rpm | shutdown occurs if speed exceeds |
| Speed | Engine speed range | approximately 2300-3910 | rpm | depending on load and load voltage (NOTE 1) |
| Speed | Ignition timing | 29 | degrees BTDC | |
| Speed | Ignition timing at cranking speeds | 15-18 | degrees BTDC | cranking |
| Speed | NP-30G engine speed at 0 A load (113-121 VAC) | 2250-2800 | rpm |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Engine oil | SAE 30 (summer); SAE 5W30 (winter) | API service classification SF, SG or SH | 950.0 ml | SAE 10W-30 acceptable summer substitute; DO NOT USE SAE 10W-40. Crankcase and oil filter capacity about 950ml or about 1 U.S. quart. Use no special additives. | |
| Engine oil | SAE 30 (with filter change) | 946.0 ml | Engine crankcase oil capacity with oil filter change is about 1 U.S. quart (946 ml) | ||
| Engine oil | SAE 30 summer (SAE 10W-30 acceptable substitute); SAE 5W30 winter | API service classification SF, SG or SH | 950.0 ml | Crankcase and oil filter capacity about 950ml or about 1 U.S. quart; do not use SAE 10W-40; use no special additives | |
| Engine oil | SAE 5W-20 or 5W-30 | For Service SC, SD, SE, SF or SG | below 0°C | Winter months (below 32 F / 0 C); DO NOT USE SAE 10W-40 | |
| Engine oil | SAE 5W-20 or SAE 5W-30 | For Service SC, SD, SE, SF or SG | below 0°C | Winter months (below 32 F / 0 C); do not use SAE 10W-40 | |
| Engine oil | SAE 5W-30 | API service classification SF, SG or SH | 950.0 ml | Winter months; DO NOT USE SAE 10W-40 | |
| Engine oil | SAE 30 | For Service SC, SD, SE, SF or SG | above 0°C | Summer months (above 32 F / 0 C). SAE 10W-30 is an acceptable substitute. Do not use SAE 10W-40. | |
| Engine oil | SAE 30 (SAE 10W-30 acceptable substitute) | For Service SC, SD, SE, SF or SG | above 0°C | 946.0 ml | Summer months (above 32 F / 0 C); DO NOT USE SAE 10W-40; capacity with oil filter change about 1 U.S. quart (946ml); without oil filter change about 29 fluid ounces (850ml) |
| Fuel | Clean, fresh, UNLEADED regular grade gasoline; leaded Regular acceptable substitute | Do not use gasohol; if gasoline containing alcohol is used it must not contain more than 10% ethanol. DO NOT USE GASOLINE CONTAINING METHANOL. DO NOT MIX OIL WITH THE GASOLINE. | |||
| Fuel | High quality UNLEADED gasoline (leaded REGULAR grade acceptable substitute) | If gasoline contains alcohol it must not contain more than 10 percent ethanol; do NOT use gasoline containing methanol | |||
| Fuel | High quality unleaded gasoline; leaded regular grade acceptable substitute | If gasoline contains alcohol it must not contain more than 10 percent ethanol and must be removed from the tank during storage; do NOT use any gasoline containing methanol | |||
| Fuel | LP gas (vapor withdrawal only) | Gaseous fuel systems; generator requires at least 67 cubic feet of gas per hour | |||
| Fuel | Unleaded gasoline | Leaded REGULAR grade gasoline is an acceptable substitute; if gasoline contains alcohol it must not contain more than 10 percent ethanol; do NOT use any gasoline containing methanol | |||
| Fuel | Unleaded regular gasoline | Gasoline fuel systems; leaded regular acceptable substitute; gasohol not recommended (max 10 percent ethanol); do not use methanol; do not mix oil with gasoline | |||
| Fuel | Unleaded, regular grade gasoline | Leaded regular may be used if unleaded unavailable. Gasohol not recommended; if used max 10% ethanol. DO NOT use methanol. Do not mix oil with gasoline. | |||
| Other | LP gas (vapor withdrawal) or natural gas | Gaseous fuel system; generator requires at least 67 cubic feet of gas per hour | |||
| Other | LP gas or natural gas (gaseous fuel systems) | Generator requires at least 67 cubic feet of gas per hour; use only approved components |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
⚠ Engine should be at room temperature with piston at TDC of compression stroke
Tools: Allen wrench, Feeler gauge, Crows foot
⚠ Do NOT adjust the fuel-air mixture excessively lean; can result in engine damage.
⚠ Do NOT adjust the fuel-air mixture excessively lean. An excessively lean mixture can result in engine damage.
⚠ Do not overbend the spring clip or the clip will lose its clamping force
Tools: Pliers
Tools: Allen wrench, feeler gauge, torque wrench, crow's foot
Tools: spark tester
⚠ All Stator leads must be isolated from other components, especially circuit boards, before performing tests. The high voltages used in testing insulation resistance will damage electronic components.
Tools: Hi-Pot tester or Megohmmeter
Tools: VOM (volt-ohm-milliammeter)
Tools: VOM (volt-ohm-milliammeter)
⚠ DO NOT attempt to test the Genistor until ALL leads have been disconnected. It MUST be completely disconnected from the circuit or all test results are invalid.
Tools: VOM (volt-ohm-milliammeter)
⚠ All stator leads must be disconnected and isolated before testing.
Tools: Volt-Ohm-Milliammeter (VOM)
Tools: VOM (volt-ohm-milliammeter)
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Voltage | Phase | Connection | Leads | Notes |
|---|---|---|---|---|
| Battery Charge Rectifier (BCR) | 66 (Brown) | |||
| Battery Charge Rectifier BCR | 77 (Brown) | Stator lead | ||
| CCG Circuit Board (CCB) | PS1 (Brown) | Stator lead | ||
| CCG Circuit Board (CONN4) | PS1 (Brown) | Pin 1 of CONN4 connector | ||
| Engine Controller Board (J1 pin 1) | 56 | Delivers 12 VDC to Starter Contactor while cranking only | ||
| Genistor (G) | SL2 (Brown) | Stator lead | ||
| Grounding Terminal | 55 (Black) | Stator lead | ||
| Ignition Sensor | RED (+) | Battery voltage from Ignition Module to Ignition Sensor | ||
| Lead 11 (Blue) connects to Main Circuit Breaker CB1 | 11 / Blue | |||
| Lead 55 (Black) connects to Grounding Terminal | 55 / Black | |||
| Lead 66 (Brown) connects to Battery Charge Rectifier BCR | 66 / Brown | |||
| Lead 77 (Brown) connects to Battery Charge Rectifier BCR | 77 / Brown | |||
| Lead AC1 (Gray) connects to Genistor | AC1 / Gray | |||
| Lead AC2 (Yellow) connects to Genistor | AC2 / Yellow | |||
| Lead PS1 (Brown) connects to CCG Circuit Board (CCB) | PS1 / Brown | |||
| Lead PS2 (Yellow) connects to CCG Circuit Board (CCB) | PS2 / Yellow | |||
| Lead SL1 (Orange) connects to Genistor | SL1 / Orange | |||
| Lead SL2 (Brown) connects to Genistor | SL2 / Brown | |||
| Lead TIM1 (Orange) connects to CCG Circuit Board (CCB) | TIM1 / Orange | |||
| Lead TIM2 (Gray) connects to CCG Circuit Board (CCB) | TIM2 / Gray | |||
| Main Circuit Breaker (CB1) | 11 (Blue) | |||
| Main Circuit Breaker CB1 | 11 (Blue) | Stator lead | ||
| 120 | Single Phase | T1 (black) is hot; T2 (white) is neutral | T1 (black), T2 (white), green ground wire | Grounded neutral; lead T2 internally connected to ground. Line T1 protected against overload by the circuit breaker (CB1). Use T1-T2 for 120 volts, 1-phase, 60 Hz AC loads. Single voltage AC connection system. |
| 120 | Single Phase | T1 (black) line, T2 (white) neutral internally connected to ground | T1 (black), T2 (white), green ground wire | Single voltage AC connection system; grounded neutral. Line T1 protected by circuit breaker (CB1). |
| 120 | single phase | T1 (black) is hot; T2 (white) is the neutral load and internally connected to ground; green lead (0) connects to ground in the RV junction box | T1 (black), T2 (white), 0 (green) | Figure 1 - Connection for 120 Volts Only; grounded neutral; AC connection system protected by a circuit breaker |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| 78601 | ELEMENT, AIR FILTER | air_filter |
| 86311 | FUEL FILTER | fuel_filter |
| 78629 | GASKET, BREATHER | gasket |
| 78631 | GASKET, CARBURETOR/SKIRT | gasket |
| 87478 | GASKET, OIL FILTER ADAPTOR | gasket |
| 89096 | GASKET, CRANK CASE FLANGE | gasket |
| 89476 | GASKET, EXHAUST | gasket |
| 90051 | GASKET, CARB/SPACER/HEAD | gasket |
| 90536 | GASKET, AIR CLEANER OUTLET | gasket |
| 94643 | GASKET, OIL DRAIN PLUG | gasket |
| 96362 | GASKET, ROCKER COVER | gasket |
| 96459 | GASKET, CARB/INLET/ADAPTOR | gasket |
| A8822 | GASKET, CYLINDER HEAD | gasket |
| 30340 | 1/4" FUEL LINE (8" LONG) | hose |
| 82580D | 3/16" CARBURETOR LINE (4" LONG) | hose |
| 86710 | HOSE, CARBURETOR INLET | hose |
| 89062 | HOSE, BREATHER | hose |
| 70185 | FILTER, OIL | oil_filter |
| 52617 | DRAIN PLUG, M12 x 1.75" LONG | other_service |
| 65795 | Battery Charge Rectifier | other_service |
| 77604 | HOUR METER | other_service |
| 86275 | GENISTOR, TRIAC MODULE | other_service |
| 86711 | MODULE, IGNITION | other_service |
| 86714 | SCREEN, OIL PICK-UP | other_service |
| 86730 | TUBE, EXHAUST OUTLET | other_service |
| 86731A | ASSEMBLY, MUFFLER | other_service |
| 89049B | COIL, IGNITION | other_service |
| 89680 | SPARK ARRESTOR | other_service |
| 90145 | 30A Circuit Breaker (all units); 30A Circuit Breaker Q-70G | other_service |
| 90881A | ASSEMBLY, CARBURETOR | other_service |
| 92234 | RV CONTROL BOARD | other_service |
| 94468-A | Manual Part No. 94468-A | other_service |
| A961 | FUSE, 7.5A. AGC | other_service |
| A9969 | ASSEMBLY, PCB CCG | other_service |
| 90475 | FUEL PUMP | pump |
| 81695 | SEAL, OIL-CRANKSHAFT | seal |
| 88156 | SEAL VALVE-INTAKE | seal |
| 89045 | SEAL, WASHER EXH. PIPE | seal |
| 89048 | SEAL, OIL FILTER HOLE | seal |
| 90071 | O-RING, 1.062" I.D. | seal |
| 90072 | O-RING .562" I.D. | seal |
| 60108 | GASKET, OIL FILTER SUPPORT | sensor |
| 77667 | Oil Pressure Switch | sensor |
| 86697 | ASSEMBLY IGNITION SENSOR | sensor |
| 94090 | SWITCH-THERMAL, OIL TEMP. | sensor |
| 72347 | SPARK PLUG-CHAMPION R12YC | spark_plug |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
The Generac GN-190 or GN-220 (see NOTE 2) powers 1 generator set(s), including Generac NP-30G.
A commonly reported issue on generators using the Generac GN-190 or GN-220 (see NOTE 2) is: Low Voltage Shutdown.