Name: Generac NP-30G Generator Set
Brand: Generac

Service parts for the NP-30G

Grouped by system, with how many of each the parts manual calls for.

Air intake

1 required

78601Air filter$17.34eBay

Fuel system

1 required

86311Fuel filtersee priceAmazon

Oil system

2 required

70185Oil filter$18.99eBay

5W-30Oil$47.95eBay

Ignition

1 required

72347Spark plug$7.19Amazon

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Fuel	Gasoline
Frequency	60.0 Hz
Controller	Computer Board, Computer Board (CCB)
Oil capacity	0.95 L
Alternator	Permanent Magnet Type (2-phase stator)
Voltage options	120 V
Phase	1-Phase
Rated current	25 A
Circuit breaker	30 A
Battery cranking	400 CCA
Battery voltage	12 V
Battery quantity	1

Engine

Generac GN-190 / GN-220

Oil capacity	0.85 L
Aspiration	Natural

Maintenance & consumables

for the Generac GN-190 / GN-220

Item	Spec	Capacity	Part #	Interval
Air filter	ELEMENT, AIR FILTER		78601	25 hr	Amazon $25.99 eBay $17.34
Fuel filter	FUEL FILTER		86311	100 hr	Amazon eBay KuduParts $28.00
Oil filter	FILTER, OIL		70185	50 hr	Amazon $28.95 eBay $18.99 KuduParts $11.00
Battery	12 VDC automotive storage battery; 70 amp-hours / 360 cold-cranking amperes above 32F (0C); 95 amp-hours / 450 cold-cranking amperes below 32F (0C)		—
Belt			—
Coolant			—
Oil		24.0 oz	5W-30	25 hr	Amazon eBay $47.95
Spark plug	Recommended Spark Plugs: Champion RC12YC; Spark Plug Gap 0.030 inch (0.8mm)		72347	100 hr	Amazon $7.19 eBay $9.99

Service intervals

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.

Service specifications

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.

Recommended fluids

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.

Procedures

Adjusting Valve Clearance adjustment

⚠ Engine should be at room temperature with piston at TDC of compression stroke

Tools: Allen wrench, Feeler gauge, Crows foot

Loosen the rocker arm jam nut.
Use an allen wrench to turn the pivot ball stud while checking clearance with a feeler gauge.
When clearance is correct, hold the pivot ball stud and tighten the rocker arm jam nut with a crows foot.
Tighten the jam nut to 65-85 inch-pounds torque.
Recheck valve clearance to make sure it did not change.

Carburetor Adjustment (Idle Jet) adjustment

⚠ Do NOT adjust the fuel-air mixture excessively lean; can result in engine damage.

Turn the idle jet inward (clockwise) until it just contacts its seat; do not force.
Turn the idle jet outward (counterclockwise) 1-1/8 turns.
Start engine and let it warm up about five minutes.
With engine at no-load, turn idle jet clockwise (leaner) until speed decreases or fluctuates.
Turn idle jet counterclockwise (richer) until speed decreases/fluctuates or black smoke appears.
Very slowly turn idle jet clockwise until speed just stabilizes or black smoke just stops.

Carburetor Idle Jet Adjustment adjustment

⚠ Do NOT adjust the fuel-air mixture excessively lean. An excessively lean mixture can result in engine damage.

Turn the idle jet inward (clockwise) until it just contacts its seat; DO NOT FORCE.
Turn the idle jet outward (counterclockwise) 1-1/8 turns to allow the engine to start and warm up.
Run the engine at no-load and turn the idle jet clockwise (leaner) until engine speed starts to decrease or fluctuate.
Turn the idle jet counterclockwise (richer) until speed decreases/fluctuates or black exhaust smoke appears.
Very slowly turn the idle jet clockwise (leaner) until engine speed just stabilizes or black smoke just stops.

Throttle Linkage Adjustment adjustment

⚠ Do not overbend the spring clip or the clip will lose its clamping force

Tools: Pliers

Start the generator, then shut it down right away and watch the throttle lever rotate counterclockwise.
There should be a gap of 0.003 inch (0.08-0.5mm) between the stop tab and the stop block.
With pliers lightly compress the spring clip so the linkage rod slides freely.
Rotate the throttle lever to increase or decrease the gap to 0.003 inch clearance.
Release spring clip to secure the adjustment.

Valve Clearance Adjustment adjustment

Tools: Allen wrench, feeler gauge, torque wrench, crow's foot

Rotate the crankshaft until the piston is at top dead center (TDC) of its compression stroke; both valves should be closed.
Loosen the rocker arm jam nut.
Use an Allen wrench to turn the pivot ball stud while checking clearance between rocker arm and valve stem with a feeler gauge.
When clearance is correct, hold the pivot ball stud with the Allen wrench while tightening the jam nut with a crow's foot.
Recheck the valve clearance after tightening the jam nut.

Spark Test (Ignition System) diagnostic

Tools: spark tester

Disconnect the high tension lead from the spark plug.
Attach the spark plug high tension lead to the spark tester terminal.
Connect the spark tester clamp to the engine cylinder head.
Crank the engine rapidly; the engine must be turning at 350 rpm or more.
If spark jumps the tester gap, the ignition system is operating satisfactorily.

Test All Stator Windings to Ground (Insulation Resistance) diagnostic

⚠ 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

Disconnect and isolate all Stator leads before starting tests.
Connect the ends of all Stator leads together; make sure none touch any terminal or part of the generator.
Connect one tester probe to the junction of all Stator leads and the other to a clean frame ground on the Stator.
Apply a voltage of 1000 volts for about 1 second.
If insulation resistance is low, clean and dry the Stator and repeat the test; if it fails again replace the Stator assembly.

Testing the Battery Charge Circuit diagnostic

Tools: VOM (volt-ohm-milliammeter)

Disconnect Wire 77 at the Battery Charge Rectifier (BCR).
Disconnect Stator output Wire 66 at the BCR.
Disconnect Wire 55.
Set a VOM to Rx1 and zero the meter.
Connect the VOM test leads across Wires 77 and 55, then across Wires 66 and 55; note both resistance readings.
With the unit running, measure AC voltage at the Wires 66 and 77 terminals; if no AC voltage, an open circuit exists in Wire 66 or 77.
With engine running, check for DC voltage between the BCR Wire 55 and frame ground; if AC was present but DC is not, the BCR is defective.

Testing the Fuel Lockoff Solenoid diagnostic

Tools: VOM (volt-ohm-milliammeter)

Set a VOM to read battery voltage (12 VDC).
Connect the VOM test leads across Wire 14 (Red) at the solenoid and a clean frame ground.
Set the fuel primer switch on the generator panel to its ON position.
The meter should indicate battery voltage and the solenoid should energize open.
If battery voltage is indicated but the solenoid does not energize, replace the lockoff solenoid.
If battery voltage is not indicated, a problem exists in the DC control system.

Testing the Genistor diagnostic

⚠ 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)

Disconnect all wires from the Genistor before testing.
Set a VOM to a resistance scale allowing 20-60 ohms to be read and zero the meter.
Connect one VOM lead to COM and the other to terminals G1, G2, G3 and G4 one at a time; each should read 20-60 ohms.
Set the VOM to Rx1; connect across COM terminal and the center screw; should read continuity.
Check continuity across each AC1, AC2, SL1 and SL2 screw to its terminal.
Set VOM to Rx10,000 or Rx1K; there should be no continuity (infinity) between any of the screws.
Replace the Genistor if it fails any of these tests.

Testing the Stator with a VOM diagnostic

⚠ All stator leads must be disconnected and isolated before testing.

Tools: Volt-Ohm-Milliammeter (VOM)

Disconnect stator power phase leads AC1, AC2, SL1, SL2 at the Genistor and lead 11 at the main circuit breaker.
Isolate all leads and ensure none touch the frame.
Set VOM to Rx1 scale and zero the meter.
Connect one test lead to lead 11; measure resistance to AC1, AC2, SL1 and SL2 individually.
To test short-to-ground, set VOM to Rx10,000 or Rx1K and measure each lead to clean frame ground (should read infinity).
Test for shorts between windings by measuring between pairs (PS1-AC1, AC1-77, AC1-TIM1, PS1-TIM1, PS1-77, TIM1-77).

Testing the Stepper Motor diagnostic

Tools: VOM (volt-ohm-milliammeter)

Unplug the Stepper Motor connector from its receptacle on the CCG circuit board.
Set a VOM to its Rx1 scale and zero the meter.
Connect one probe to the connector pin for the RED wire and the other probe to the ORANGE, YELLOW, BROWN and BLACK pins in turn; each should read 19-21 ohms.
To test for a shorted condition, set the VOM to Rx10,000 or Rx1K and zero the meter.
Connect one probe to the RED wire connector pin and the other to the Stepper Motor case; meter should read infinity.
Replace the Stepper Motor if it fails any part of the test.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

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.

Common questions

What engine is in the Generac NP-30G?

The Generac NP-30G is powered by the Generac GN-190 / GN-220 engine.

Is the Generac NP-30G diesel or gas?

The Generac NP-30G runs on Gasoline.

What is the oil capacity of the Generac NP-30G?

The Generac GN-190 / GN-220 engine in the Generac NP-30G has an oil capacity of 0.85 liters.

Which alternator is fitted to the Generac NP-30G?

The Generac NP-30G uses a Permanent Magnet Type (2-phase stator) alternator.

Which oil filter part number does the Generac NP-30G take?

The Generac NP-30G uses oil filter part number 70185.

What fuel filter does the Generac NP-30G use?

The Generac NP-30G uses fuel filter part number 86311.

What air filter fits the Generac NP-30G?

The Generac NP-30G uses air filter part number 78601.

Troubleshooting

Symptoms & remedies

Symptom	Cause	Remedy
Engine won't crank.	1. 15 amp fuse is blown 2. Loose, corroded or defective battery cables. 3. Defective engine Start/Stop switch. 4. Defective starter contactor. 5. Defective starter motor. 6. Low or defective battery.	1. Replace 15 amp fuse. 2. Tighten, clean or replace battery cables as necessary. 3. Replace Start/Stop switch. 4. Replace contactor. 5. Replace starter motor. 6. Change or replace battery.
Engine cranks but won't start.	1. Out of fuel. 2. Fuel pump is defective. 3. Open Wire #14 from Eng. Control Bd. 4. Engine is flooded. 5. Spark plug defective.	1. Replenish fuel. 2. Replace fuel pump. 3. Reconnect wire. 4. Wait 5-10 min. before trying. 5. Clean, regap or replace plug.
Engine starts hard, runs rough, low full load power.	1. Air cleaner plugged or damaged. 2. Defective spark plug. 3. Loose spark plug boot.	1. Clean or replace as needed. 2. Clean, regap or replace plug. 3. Press boot on securely.
Engine starts, shuts down when Start/Stop switch is released.	1. Engine oil is low. 2. Engine is overheated. 3. Defective Low Oil Pressure System. 4. Defective Engine Control Board. 5. Defective Computer Contro! Board.	1. Check oil; add as needed. 2. Check for adequate ventilation. 3. Have serviced/replaced. 4. Have board serviced/replaced. 5. Have board serviced/replaced.
Start/Stop switch at Stop, engine continues to run.	1. Defective Start/Stop switch.	1. Replace switch.
No AC voltage can be measured across Stator connections at the Battery Charge Rectifier (BCR)	An open circuit condition probably exists in Wire 66 (Brown), or Wire 77 (Brown).	Replace Stator Assembly

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Generac NP-30G troubleshooting guide (29 entries) →

Parts

134

Part #	Description	Qty	System
007-91297	STARTER CONTACTOR	1	Starter	eBay
066386	BRUSH HOLDER	1	Brush	Amazon eBay
070185	Oil Filter	1	Oil filter	Amazon $28.95 eBay $30.00 FridayParts $45.99
072347	SPARK PLUG	2	Spark plug	Amazon $34.90 eBay $1.99
078631	GASKET CARBURETOR/MANIFOLD	1	Gasket	eBay $10.99
080336	OIL PICK-UP ASSEMBLY	1	Pump	eBay
081695	OIL SEAL	2	Seal	eBay
0830490	REGULATOR VOLTAGE	1	Avr	eBay $66.97
086254	"O" RING	1	Seal	eBay
086729	CONTACTOR, STARTER	1	Starter	Amazon eBay $14.34
087769	FUEL FILTER	1	Fuel filter	Amazon $16.88 eBay
088156	SPARK PLUG	1	Seal	Amazon eBay
089096	CRANKCASE GASKET	1	Gasket	Amazon eBay $9.99
089476	GASKET, EXHAUST	1	Gasket	eBay $9.00
090051	GASKET, MANIFOLD/HEAD	1	Gasket	eBay $6.99
091846	GASKET, CARB/ADAPTOR	1	Gasket	eBay $12.00
091848	GASKET, OIL PSI PAD	1	Gasket	eBay $29.99
094090	SWITCH, THERMAL 293F	1	Sensor	eBay $14.99
0A8584	SWITCH OIL PRESSURE	1	Sensor	Amazon $23.50 eBay FridayParts $31.60
0A8822	CYLINDER HEAD GASKET	1	Gasket	Amazon eBay $13.96
0C8754	ROCKER COVER GASKET	1	Gasket	eBay $20.00
0C9706	STARTER ASSEMBLY	1	Starter	eBay
0D3262	AIR FILTER ELEMENT	1	Air filter	Amazon eBay
0D4511	PRECLEANER, AIR	1	Air filter	Amazon $9.99 eBay $39.99 FridayParts $34.99
0D7513	PUMP, FUEL	1	Pump	Amazon eBay
0D7515	FUEL FILTER	1	Fuel filter	Amazon eBay
0D7666	BREATHER TUBE	1	Hose	eBay
0D8372	GASKET, CARB TO AIRBOX	1	Gasket	eBay
0D8981	FILTER GASKET RV	2	Gasket	Amazon eBay
0D9723	ELEMENT AIR FILTER	1	Air filter	Amazon $11.39 eBay $16.85
0E0017	GASKET, MUFFLER TAIL PIPE BOX	1	Gasket	Amazon eBay
21704	GASKET, CYLINDER HEAD	1	Gasket	Amazon eBay
30340	1/4" FUEL LINE (8" LONG)	1	Hose	Amazon $39.99 eBay
34043	Filter, air - solar	1	Air filter	Amazon eBay
34174	Gasket, exhaust	1	Gasket	Amazon eBay
40173	CLAMP, HOSE #5 35° 22473 8 FLAT WASHER 1/4"	2	Hose	Amazon eBay
60108	GASKET, OIL FILTER SUPPORT	1	Sensor	Amazon eBay
70185	FILTER, OIL	1	Oil filter	Amazon $28.95 eBay $18.99 KuduParts $11.00
72347	SPARK PLUG-CHAMPION R12YC	1	Spark plug	Amazon $7.19 eBay $9.99
77667	Oil Pressure Switch	1	Sensor	Amazon $9.99 eBay $9.99
78601	ELEMENT, AIR FILTER	1	Air filter	Amazon $25.99 eBay $17.34
78629	GASKET, BREATHER	2	Gasket	Amazon eBay FridayParts $41.00
78631	GASKET, CARBURETOR/SKIRT	1	Gasket	Amazon eBay $10.99
81695	SEAL, OIL-CRANKSHAFT	2	Seal	Amazon eBay $15.95
825800	3/16" CARBURETOR LINE (4" LONG)	1	Hose	Amazon eBay
82580D	3/16" CARBURETOR LINE (4" LONG)	1	Hose	Amazon eBay
83152	GEROTOR, INNER	1	Pump	Amazon eBay
83153	GEROTOR, OUTER	1	Pump	Amazon eBay
86311	FUEL FILTER	1	Fuel filter	Amazon eBay KuduParts $28.00
86697	ASSEMBLY IGNITION SENSOR	1	Sensor	Amazon eBay KuduParts $32.00
86707	GASKET, CARB/INLET ADAPTOR	1	Gasket	Amazon eBay $18.73
86710	HOSE, CARBURETOR INLET	1	Hose	Amazon eBay
86729	Contactor, Starter	1	Starter	Amazon eBay $18.99 KuduParts $41.00
87478	GASKET, OIL FILTER ADAPTOR	1	Gasket	Amazon eBay
88156	SEAL VALVE-INTAKE	1	Seal	Amazon eBay
89045	SEAL, WASHER EXH. PIPE	1	Seal	Amazon eBay
89048	SEAL, OIL FILTER HOLE	1	Seal	Amazon eBay
89062	HOSE, BREATHER	1	Hose	Amazon eBay
89096	GASKET, CRANK CASE FLANGE	1	Gasket	Amazon eBay
89476	GASKET, EXHAUST	1	Gasket	Amazon eBay $14.82 FridayParts $272.43
90051	GASKET, CARB/SPACER/HEAD	2	Gasket	Amazon eBay $6.99
90071	O-RING, 1.062" I.D.	1	Seal	Amazon eBay
90072	O-RING .562" I.D.	1	Seal	Amazon eBay
90475	FUEL PUMP	1	Pump	Amazon $59.99 eBay $25.93
90536	GASKET, AIR CLEANER OUTLET	1	Gasket	Amazon eBay
90537	SEAL, OIL FILTER HOLE	1	Seal	eBay
92000	HOSE-3/8 I.D. x 11-1/2" LONG	1	Hose	eBay
94090	SWITCH-THERMAL, OIL TEMP.	1	Sensor	Amazon eBay $19.95
94643	GASKET, OIL DRAIN PLUG	1	Gasket	Amazon eBay
96362	GASKET, ROCKER COVER	1	Gasket	Amazon eBay
96459	GASKET, CARB/INLET/ADAPTOR	1	Gasket	Amazon eBay
99948	STARTER MOTOR	1	Starter	Amazon eBay $120.00
A3638	SEAL, WASHER EXH. PIPE	1	Seal	eBay
A8822	GASKET, CYLINDER HEAD	1	Gasket	Amazon eBay
023484S	BUSHING, 1.09" SNAP	1	Service part / kit	Amazon eBay
053623	CIRCUIT BREAKER	1	Service part / kit	eBay $25.00
065795	BATTERY CHARGER RECTIFIER	1	Service part / kit	Amazon eBay
073159	BEARING	1	Service part / kit	Amazon eBay
081675	ASSEMBLY, IGNITION COIL	1	Service part / kit	eBay
088057	PISTON	1	Service part / kit	Amazon eBay $14.99
088396A	PUSH ROD	2	Service part / kit	eBay
088401	VALVE SPRING	2	Service part / kit	eBay $9.95
088411	PISTON RING SET	1	Service part / kit	Amazon eBay
089680	SPARK ARRESTER	1	Service part / kit	Amazon eBay $7.50
090145	CIRCUIT BREAKER 30 X 1	1	Service part / kit	eBay $37.90
0922340	CONTROLLER P.C.B.	1	Service part / kit	eBay
0A9611	FUSE 7.5 AMP	1	Service part / kit	Amazon eBay $19.99
0C3590	EXHAUST VALVE	1	Service part / kit	eBay $10.95
0C3591	INTAKE VALVE	1	Service part / kit	eBay $19.95
0C3592	VALVE SPRING KEEPER	4	Service part / kit	eBay $24.70
0D7440	MUFFLER	1	Service part / kit	eBay
0D8332	CARBURETOR	1	Service part / kit	eBay $45.89
0D8590	ASSEMBLY, BI-METAL/HEATER	1	Service part / kit	eBay $140.00
0D8591	SOLENOID, CHOKE	1	Service part / kit	eBay
22676	15 Amp Fuse	1	Service part / kit	Amazon $20.06 eBay
32150	Regulator, vaporizer - LPG	1	Service part / kit	Amazon eBay FridayParts $91.86
32151	Regulator, direct-operated	1	Service part / kit	Amazon eBay
34108	Regulator, low pressure	1	Service part / kit	Amazon eBay
34359	Muffler, solar - EES	1	Service part / kit	Amazon eBay
49721	MODULE, IGNITION	1	Service part / kit	eBay
52617	DRAIN PLUG, M12 x 1.75" LONG	1	Service part / kit	eBay
65795	Battery Charge Rectifier	1	Service part / kit	Amazon eBay $33.96
77604	HOUR METER	1	Service part / kit	eBay $27.00
86275	GENISTOR, TRIAC MODULE	1	Service part / kit	eBay
86711	MODULE, IGNITION	1	Service part / kit	eBay KuduParts $135.00
86714	SCREEN, OIL PICK-UP	1	Service part / kit	eBay
86730	TUBE, EXHAUST OUTLET	1	Service part / kit	eBay
86731A	ASSEMBLY, MUFFLER	1	Service part / kit	Amazon eBay
87798	Start/Stop Switch	1	Service part / kit	eBay
88057	PISTON, 75 DIA.	1	Service part / kit	eBay FridayParts $753.89
88411	SET, PISTON RING (STD. SIZE)	1	Service part / kit	eBay
89049	ASSY., IGNITION COIL	1	Service part / kit	eBay $83.80
89049B	COIL, IGNITION	1	Service part / kit	eBay
89263	ASSEMBLY, OIL FILL CAP	1	Service part / kit	eBay
89680	SPARK ARRESTOR	1	Service part / kit	Amazon eBay $14.99
89923	SEPARATOR, OIL BREATHER	1	Service part / kit	eBay
90081	VALVE, INTAKE	1	Service part / kit	eBay $13.99
90082	VALVE, EXHAUST	1	Service part / kit	eBay
90145	30A Circuit Breaker (all units); 30A Circuit Breaker Q-70G	1	Service part / kit	eBay
90881A	ASSEMBLY, CARBURETOR	1	Service part / kit	Amazon eBay
91306	Choke Solenoid	1	Service part / kit	eBay
92059	STEPPER MOTOR	1	Service part / kit	eBay
92113	dk a_i Dh ok	1	Service part / kit	Amazon eBay
92234	RV CONTROL BOARD	1	Service part / kit	Amazon eBay
94468-A	Manual Part No. 94468-A		Service part / kit	Amazon eBay $26.21
A2774A	CARBURETOR ASSEMBLY (LP)	1	Service part / kit	Amazon eBay
A4603	FUEL SOLENOID 12VDC	1	Service part / kit	eBay
A5776	BALL, OIL PRESSURE	1	Service part / kit	Amazon eBay $19.99
A6187	INVERTER ASSEMBLY	1	Service part / kit	eBay
A8592	CIRCUIT BREAKER, 10A	1	Service part / kit	eBay
A961	FUSE, 7.5A. AGC	1	Service part / kit	eBay
A9611	FUSE, 7.5A. AGC	1	Service part / kit	eBay
A9969	ASSEMBLY, PCB CCG	1	Service part / kit	eBay
S0881A	ASSEMBLY, CARBURETOR	1	Service part / kit	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.

Fuel consumption

Rating	Load	L/h	gal/h
		0.49	0.13
	50%	0.76	0.2
	100%	1.51	0.4
Continuous		0.49	0.13
Continuous	50%	0.76	0.2
Continuous	100%	1.51	0.4

Available documents

Owner's manual — A5929 (Generac)Owner's manual — A9400 (Generac)Owner's manual — A9400 (Generac)Parts manual — Chart3 (Generac)Service manual — 94468A (Generac)Service manual — 94468A (Generac)Service manual — Generac Service Manual 94468A (Generac)