HomeEnginesCummins/Onan B3.3G2

Cummins/Onan B3.3G2 Engine

The Cummins/Onan B3.3G2 is a 3.3 L turbocharged engine rated at 1500 rpm. It powers generator sets from Cummins/Onan, including the B3.3-G2, C50 D6 and C55 D5.

Also known as: B3.3G2, Cummins B3.3G2

3.3 L
Displacement
1500 rpm
Rated speed

Engine specifications

Displacement3.3 L
Aspirationturbocharged
Rated speed1500 rpm

Common problems

15
  • Weakness and Sleepiness
    Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
  • Vomiting
    Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
  • Oil Pressure Sensor OOR - Low Code 141
  • Oil Pressure Sensor OOR - High Code 135
  • Muscular Twitching
    Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
  • Low Battery Voltage Code 441
  • Inability to Think Coherently
    Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired.
  • High Battery Voltage Code 442
  • Fuel contact with hot engine or exhaust
    Fix: Do not permit any flame, cigarette, pilot light, spark, arcing equipment, or other ignition source near the generator set or fuel tank. Fuel lines must be adequately secured and free of leaks. Use an approved flexible line for fuel connection at the engine. Do not use copper piping on flexible lines as it will become brittle if continuously vibrated or repeatedly bent. Ensure all fuel supplies have a positive shutoff valve.
  • Exhaust gases are deadly
    Fix: Provide an adequate exhaust system to properly expel discharged gases away from enclosed or sheltered areas, and areas where individuals are likely to congregate. Visually and audibly inspect the exhaust system daily for leaks per the maintenance schedule. Ensure that exhaust manifolds are secured and not warped. Do not use exhaust gases to heat a compartment. Make sure the unit is well ventilated.
  • Engine Speed High (Shutdown) Code 234
  • Engine Oil Pressure Low (Warning) Code 143
  • Engine Oil Pressure Low (Shutdown) Code 415
  • Engine Fail to Start Code 359
  • Engine Coolant Temperature OOR Low (Warning) Code 144

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan B3.3G2.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterAir Cleaner Element0140-3765 Amazon eBay

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

20
ItemActionHoursMonthsNotes
Exhaust systemInspect8 hrVisually and audibly inspect the exhaust system daily for leaks per the maintenance schedule; check for corrosion, obstruction, and leaks every time you start the generator set and every eight hours when you run it continuously
Air cleaner restriction indicatorCheck24 hrIf service indicator shows red, replace air cleaner elements and reset indicator.
Coolant heaterCheck24 hrVerify power and operation; check for leaks.
Coolant level of radiator(s)Check24 hrTop up with Cummins recommended coolant mix if low.
Engine oil levelCheck24 hrTop up with recommended oil if low.
Fuel level in fuel tankCheck24 hrRefill as required.
Fuel lines and hosesCheck24 hrCheck for leaks, worn or damaged hoses.
Generator set enclosureInspect24 hrWalk-around; ensure no inlets/outlets covered.
Operator panel operationCheck24 hrCheck display; replace component if not functioning.
Air intake system for leaksInspect50 hrVisually inspect; check audibly when running.
Battery connectionsCheck50 hrVerify connections are secure.
Charge alternatorCheck50 hrCheck visually and audibly when running.
Coolant lines and radiator hosesCheck50 hrCheck for leaks, wear, and cracks.
Cooling fan bladesInspect50 hrVisually inspect through guarding.
Drive belt condition and tensionCheck50 hrCheck for wear or slippage.
Exhaust components and hardwareCheck50 hrVisually inspect; check audibly when running.
Radiator air flowInspect50 hrCheck for blockage, debris, wear or damage.
Engine oil and filtersReplace200 hrFirst service — After the initial 50 hour interval and every 200 hours thereafter (footnote 3).
Fuel filter and water separatorReplace500 hr
Cooling system coolantReplace24 mo

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

60
TypeItemValueUnitCondition
GapMPU sensor tip to ring gear teeth clearance0.5 - 0.6mm
OtherAFLEX-H (shake table test datum)<=3.200gAC156, tri-axial, 5% damping SRS
OtherAFLEX-V (shake table test datum)<=1.333gAC156, tri-axial, 5% damping SRS
OtherARIG-H (shake table test datum)<=2.400gAC156, tri-axial, 5% damping SRS
OtherARIG-V (shake table test datum)<=0.533gAC156, tri-axial, 5% damping SRS
OtherFlywheel teeth (Teeth Pulses Per Revolution)110PCC setting
OtherGlow plug preheat time5glow plug calibration
OtherGlow plug total glow plug time60glow plug calibration
OtherGround snow load limit30psfFor indoor (covered) and outdoor (exposed) installation
OtherHorizontal design seismic coefficient (z/h = 0.0)1.440gCertified seismic design level, IBC Importance IP <= 1.5, Soil Classes A-E, Risk Categories I-IV, Design Categories A-F, SDS <= 2.000 g
OtherSDS (g) at z/h=1 for C10 D6 - C60 D62.0gCertified SDS, z/h = 1
OtherSDS (g) at z/h=1 for C50 D6C - C125 D6C2.5gCertified SDS, z/h = 1
OtherSpeed/frequency mismatch threshold2.0HzPCC setting
OtherSpeed/frequency mismatch threshold time1.5secondsPCC setting
OtherZPA-H (shake table test datum)<=2.160gAC156, tri-axial, 5% damping SRS
OtherZPA-V (shake table test datum)<=0.480gAC156, tri-axial, 5% damping SRS
ResistanceBattery ground connection resistancemore than 1Ohmindicates repair needed
ResistanceCoolant temperature sensor resistance540 Ohms at -40 F to 1100 Ohms at 100 F; 1100 Ohms at 100 F to 1800 Ohms at 230 FOhm
ResistanceDiode reverse direction resistance (good)above 20MOhmreverse direction at 1000 VDC
ResistanceStarter solenoid wiring continuity (relay 87 to SW)less than 5Ohm
ResistanceTemperature sender harness lead resistanceless than 0.5Ohmeach lead from connection to PCC
ResistanceVaristor resistance (good)greater than 100MOhm
ResistanceWinding test conditions20Cwinding temperature for insulation measurement
ResistanceWindings minimum insulation resistance (in-service)5MOhm1 minute at 500 V test voltage
ResistanceWindings minimum insulation resistance (new)10MOhm1 minute at 500 V test voltage
SpeedFrequency-to-speed gain select30RPM/HzPCC setting
SpeedOverspeed Trip Level (60 Hz)2250PCC threshold
SpeedSecondary Overspeed Trip Speed (60 Hz)2250PCC threshold
SpeedStarter Disconnect Speed400RPMInPower setting
SpeedStarter Disconnect Speed (code 5134)450RPMInPower setting
TemperatureHigh coolant temperature shutdown threshold230 F / 110Cshutdown
TemperatureHigh coolant temperature warning threshold220 F / 105Cwarning
TemperatureLow coolant temperature warning threshold70 F (21 C)4BT3.3 engines
TorqueAir cleaner strap clamp3.4 to 4.5Nm
TorqueAlternator drive disc bolt and adaptor bolt (section 12.5)52 +/- 5Nm
TorqueAlternator drive disc bolts and adaptor bolts47 to 57Nm
TorqueBolts on engine mounting brackets to engine47 to 57Nm
TorqueBottle bolt to bracket3 to 4Nm
TorqueCAC inlet and outlet connections10 to 12Nm
TorqueCoolant reservoir bottle to fan guard10 to 12Nm
TorqueDiode into rectifier plate2.6 to 3.1Nm
TorqueEnclosure top panel bolts9.8 to 11.9Nm
TorqueEquipment grounding lug (AC load connections)13.8Nm (120 in-lb)
TorqueEquipment grounding lug (circuit breaker)13.8Nm (120 in-lb)
TorqueExhaust connections, engine3.4 to 4.5Nm
TorqueFan to hub bolt24 to 29Nm
TorqueGenerator set enclosure panel fasteners9.8 to 11.9Nm
TorqueGround lug to terminal box4.7 to 5.7Nm
TorqueM6 hex head screws9.8 to 11.9Nm
TorqueMuffler clamps (three)24 to 29Nm
TorqueMuffler end bolts (two each end)24 to 29Nm
TorqueNDE/terminal covers torque #8 star head bolt4 to 5Nm
TorqueNeutral lug (AC load connections)31.1Nm (275 in-lb)
TorqueNeutral lug (circuit breaker)31.1Nm (275 in-lb)
TorqueNeutral lug to terminal box12.3 to 15Nm
TorqueNuts to isolator stud (engine/alternator isolators)82 to 100Nm
TorqueRadiator side bracket bolts24 to 29Nm
TorqueTerminal box cover panels4.7 to 5.7Nm
TorqueTerminal box mounting bolts (6 each side)12.3 to 15Nm
Voltage12V Charging Alternator Disconnect Voltage9VDCInPower setting

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

FluidGradeStandardAmbientCapacityNotes
Coolant50/50 coolant solution (50% pure water and 50% ethylene glycol)
Coolant50/50 coolant solution (50% water / 50% ethylene glycol)
Engine oil15W407.9 L (8.35 qt)Refer to the Engine Operator Manual
FuelASTM number 2D fuelASTM 2D
GreaseDow Corning silicone heat sink compound type 340 or similarApply to base of replacement diode only

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

Fault codes

45
CodeNameMeaningSeverityAction
121Loss of Speed SenseNo engine speed signal detected from crankshaft speed or camshaft position.ShutdownInspect MPU sensor and harness; set MPU tip clearance 0.5-0.6 mm; verify calibration.
1311Customer Input #1Configurable customer input 1 fault.WarningCheck TB1-12; check external wiring; verify fault function settings.
1312Customer Input #2Configurable customer input 2 fault.WarningCheck TB1-14; check external wiring; verify fault function settings.
1317Low Coolant LevelOptional coolant level sensor indicates low coolant level.WarningAdd coolant; check coolant level sensor connections and operation; verify calibration.
1318Low FuelOptional low fuel level switch indicates low fuel.WarningAdd fuel; verify switch operation; check wiring; verify settings.
135Oil Pressure Sensor OOR - HighEngine oil pressure sensor signal out of range - shorted high.WarningInspect sensor connections; check supply 4.75-5.25 VDC and signal voltage.
141Oil Pressure Sensor OOR - LowEngine oil pressure sensor signal out of range - shorted low.WarningInspect sensor connections; check supply and signal voltage.
1417Power Down FailureThe PCC has failed to go to sleep.WarningVerify calibration; cycle B+ power; replace baseboard if fault persists.
143Engine Oil Pressure LowEngine oil pressure below low oil pressure warning threshold (40 psig for 5 seconds).WarningCheck oil level, external leaks, sensor accuracy, oil cooler, regulator, oil pump.
1433Local E-StopState of the Local Emergency Stop has been changed.ShutdownReset local E-Stop; check E-Stop switch and wiring.
1434Remote E-StopState of the Remote Emergency Stop has been changed.ShutdownReset remote E-Stop; install jumper TB1-16 to TB1-15; check switch and wiring.
1435Low Coolant TemperatureEngine coolant temperature below low coolant temperature warning threshold (70 F / 21 C).WarningVerify LCT threshold; check coolant heater operation; check ambient temperature.
1438Fail to CrankEngine failed to crank after the generator control received a start signal.ShutdownCheck battery, starter, starter solenoid, starter relay, CAM/Crank sense.
144Engine Coolant Temperature OOR LowEngine coolant temperature signal out of range - shorted low.WarningInspect sensor connections; check sensor resistance; verify calibration.
1442Weak BatteryBattery voltage dropped below weak battery voltage threshold (8 V for 2 seconds) while cranking.WarningCheck battery, connections, charging voltage, DC alternator, harness.
1446High AC VoltageOne or more phase voltages exceeded high AC voltage threshold (110% of nominal, 10 seconds).WarningCheck threshold, PCC AVR circuit, generator output connections, PMG, EBS.
1447Low AC VoltageOne or more phase voltages dropped below low AC voltage threshold (85%, 10 seconds).ShutdownCheck AVR settings, rotating rectifier diodes, overload, residual magnetism, connections.
1448UnderfrequencyFrequency dropped below underfrequency threshold (6 Hz) for 10 seconds.ShutdownCheck overrides, threshold, overload, engine governor.
1449OverfrequencyFrequency went above overfrequency threshold (6 Hz) for 10 seconds.ShutdownVerify overfrequency threshold and time delay; check engine governor.
145Engine Coolant Temperature OOR HighEngine coolant temperature signal out of range - shorted high.WarningInspect sensor connections; check sensor resistance; verify calibration.
146Engine Coolant Temperature Above NormalEngine coolant temperature exceeded warning threshold (220 F / 105 C).WarningCheck ambient temperature, coolant level, cooling components, sensor, thermostat, water pump.
1469Speed/Hz MismatchPerceived engine speed and generator set output frequency do not match.ShutdownCheck flywheel teeth (110), MPU signal, thresholds (2.0 Hz, 1.5 s), gain (30 RPM/Hz).
1471High AC CurrentGenerator output current exceeded warning limit threshold (110% for 60 seconds).WarningCheck for short, overload, CTs and CT setup, rating setup, fault override.
1472High AC CurrentGenerator output current exceeded shutdown set limit (150% for 10 seconds).ShutdownCheck for short/overload, CTs and CT setup, rating setup, fault override.
151Engine Coolant Temperature HighEngine coolant temperature exceeded shutdown threshold (230 F / 110 C).ShutdownCheck cooling system, coolant level, sensor, thermostat, water pump.
1853Annunciator Input 1 FaultCustomer fault 1 (input 1, LED 1) on the universal annunciator is active.WarningCheck condition and wiring at TB1-1; verify configuration; replace annunciator if faulty.
1854Annunciator Input 2 FaultCustomer fault 2 (input 2, LED 2) on the universal annunciator is active.WarningCheck condition and wiring at TB1-2; verify configuration; replace annunciator if faulty.
1855Annunciator Input 3 FaultCustomer fault 3 (input 3, LED 3) on the universal annunciator is active.WarningCheck condition and wiring at TB1-3; verify configuration; replace annunciator if faulty.
1944Annunciator Configuration ErrorMore than one network device configured to activate one annunciator output relay.WarningCheck network configuration and devices for duplicate use of the same relay output.
2335Excitation Fault (Loss of AC Sense)Control lost voltage sensing or lost zero cross sensing.ShutdownCheck configuration, fuse F5 (10 Amp), harness connections, residual magnetism, excitation coil, control board.
234Engine Speed HighEngine speed signals indicate engine speed greater than shutdown threshold.ShutdownCheck MPU sensor and installation; verify overspeed trip level and flywheel teeth (110).
2676Alternator Frequency ConflictAlternator line frequency and alternator excitation frequency do not match.ShutdownCheck alternator line frequency gain; check J22 and J18 connections; check harness and control board.
2677Fail to StopGenerator set continues to run after receiving shutdown command from controller.ShutdownCheck stuck fuel actuator/fuel shutoff valve; check governor module and wiring.
2729IO Module LostIntermittent data link between I/O module and PCC (no input fault levels set to Shutdown).WarningCheck AUX 101 wiring to PCC 1302; verify System IO Board Enable is disabled.
2731IO Module LostIntermittent data link between I/O module and PCC (at least one input fault set to Shutdown).ShutdownCheck AUX 101 wiring to PCC 1302; verify I/O settings.
2897Factory Memory Block CorruptThe control detected a corrupted memory block.WarningConnect with InPower 10.0+; select Initial Calibration (Recover Device).
2898Periodic or Fault Memory Block CorruptThe control detected a corrupted memory block.WarningConnect with InPower 10.0+; select Initial Calibration (Recover Device).
2899User Memory Block CorruptThe control detected a corrupted memory block.WarningConnect with InPower 10.0+; select Initial Calibration (Recover Device).
2911Trim Memory Block CorruptThe control detected a corrupted memory block.WarningConnect with InPower 10.0+; select Initial Calibration (Recover Device).
2972Field OverloadField AVR Duty Cycle operated at maximum output longer than Max Field Time parameter.ShutdownCheck voltage sensing into baseboard; check AVR output; check application.
359Engine Fail to StartEngine failed to start after expiration of last crank time.ShutdownCheck flywheel teeth setting (110), starter disconnect speed (400 RPM), fuel supply, glow plugs.
415Engine Oil Pressure LowEngine oil pressure below low oil pressure shutdown threshold (35 psig).ShutdownCheck oil level, external leaks, sensor accuracy, oil cooler, oil pump.
441Low Battery VoltageBattery voltage is low.WarningCheck battery cables, battery condition, ground connection, DC alternator, charger.
442High Battery VoltageBattery voltage above high battery threshold (16 V for 60 seconds).WarningVerify charger set to 12 VDC; check fault threshold; check engine DC alternator.
5134Unknown ShutdownPCC detected that engine RPM decreased to zero while not in run at rated mode.ShutdownCheck calibration, air intake/exhaust restriction, MPU signal, start disconnect, fuel supply.

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

Procedures

12
Disabling the AMF Feature adjustment

⚠ Must be performed by a qualified technician.

Tools: InPower service tool

  1. Connect to the PCC 1.1 or PCC 2.3 via InPower.
  2. Navigate to Adjustments->Features->Automatic Transfer Switch folder.
  3. Select the Auto Mains Failure Enable parameter.
  4. Double-click on Enabled in the Value field.
  5. Select Disabled from the pop-up choices.
  6. Select Device->Save Adjustments from the top menu bar.
  7. Click Save on the confirmation pop-up.
  8. Disconnect InPower from the PCC1302 after confirmation.
Fuel Injection Pump Speed Lever Adjustment adjustment
  1. Make sure the generator set is off and the battery is disconnected.
  2. If replacing pump or engine, discard speed adjust screw and tamper proof wire and seal.
  3. Replace the low idle screw; reuse throttle screw nut and acorn nut.
  4. Pull throttle lever back and screw new low idle screw until it contacts boss.
  5. Continue tightening until throttle lever is locked in place.
  6. Tighten the throttle lock nut.
  7. Install tamper proof wire and seal.
  8. Set the throttle lever as shown and lock it using seal wire.
AC Load Connections (Circuit Breaker) installation

⚠ Improper installation can lead to electrocution and property damage.

Tools: Insulated wrench, Torque wrench

  1. Shut down and disable the generator set (Off then E-Stop, cool down).
  2. Turn off battery charger AC and disconnect negative battery cable.
  3. Remove enclosure side panel to access main circuit breaker box.
  4. Place circuit breaker handle in OFF position.
  5. Remove four bolts holding circuit breaker cover.
  6. Connect conductors to load-side terminals, neutral lug, and grounding lug.
  7. Torque circuit breaker terminals per breaker label.
  8. Torque neutral lug to 31.1 Nm (275 in-lb).
  9. Torque equipment grounding lug to 13.8 Nm (120 in-lb).
  10. Fill stub-up openings with duct seal or mastic tape.
  11. Install circuit breaker cover.
Connect Battery installation

⚠ Do not connect battery cables until installation is complete to prevent accidental startup.

  1. Connect the positive battery terminal.
  2. Connect the negative battery terminal.
  3. Make sure black and red battery cable boots are in place.
Connecting the Battery installation

⚠ Accidental or remote starting of the generator set can cause severe personal injury or death.

  1. Press the generator set's O (Off) button and allow it to cool.
  2. Turn off and disconnect the battery charger from the AC source before disconnecting battery cables.
  3. Disconnect the negative (-) cable from the battery.
  4. Connect the positive battery terminal.
  5. Connect the negative battery terminal.
  6. Make sure black and red battery cable boots are in place.
Adding Oil maintenance

⚠ Contact with hot engines can cause severe burns.

  1. Ensure the oil fill cap area is clean.
  2. Add the appropriate amount of oil.
  3. Recheck the engine oil level.
  4. Clean up and dispose of any oil per local regulations.
Changing Engine Oil and Oil Filter maintenance

⚠ Make sure the generator set is shut down and disabled.

⚠ Avoid skin contact and breathing of vapors.

  1. Operate generator set until water temperature is approximately 60 C (140 F).
  2. Shut down and disable the generator set; disconnect negative battery cable.
  3. Drain the oil into an appropriate container.
  4. Remove the oil filter and clean the filter mounting surface.
  5. Apply a thin film of clean oil to the new filter gasket.
  6. Install new filter until gasket touches, then turn 1/2 to 3/4 more.
  7. Close drain valve and add the appropriate amount of oil.
  8. Run engine at idle; check and repair any leaks.
Checking Engine Oil Level maintenance

⚠ Crankcase pressure can blow out hot oil and cause severe burns.

⚠ Do not check oil while the engine is operating.

  1. Make sure the generator set has not run for approximately five minutes.
  2. Clean off the area surrounding the dipstick port.
  3. Pull out the dipstick and wipe it clean.
  4. Reinsert and fully seat the dipstick.
  5. Remove the dipstick and check the oil level.
  6. Reinsert and fully seat the dipstick.
Cleaning Radiator Cores Using Pressurized Water Equipment maintenance

⚠ Do not use cleaners containing ammonia.

⚠ Wear PPE when cleaning with a pressure washer or compressed air.

Tools: Industrial pressure washer, PPE

  1. Remove enclosure end panel(s) to assist cleaning.
  2. Inspect radiator exterior for obstructions.
  3. Pressure wash in the opposite direction to the airflow.
  4. Keep lance at a right angle to core, minimum 18 inches (450 mm) distance.
  5. Replace the end panel(s) where necessary.
Draining Oil maintenance
  1. Detach the oil drain hose from the side of the engine.
  2. Place the end of the drain hose into an appropriate container.
  3. Open the oil drain valve to release oil.
  4. Close the oil drain valve when sufficient oil drained.
  5. Wipe the oil drain valve clean and re-attach the drain hose.
Heavy Duty Air Cleaner Element Removal maintenance

⚠ Do not clean paper-type air cleaner elements.

  1. Wipe dirt from the cover and upper portion of air cleaner.
  2. Lift tab (3) and turn end cover (4) counterclockwise.
  3. Pull the end cover (4) away from the housing (1).
  4. Remove the air filter element (2) from the housing.
  5. Dispose of the dirty element per local environmental requirements.
Locking the Generator Set Out of Service maintenance

⚠ Accidental or remote starting of the generator set can cause severe personal injury or death.

Tools: Insulated wrench

  1. Press Off switch, then press E-Stop button.
  2. Thoroughly ventilate the generator set before disconnecting any leads.
  3. Turn off and disconnect the heater (where fitted) from AC source.
  4. Turn off and disconnect the battery charger (where fitted) from AC source.
  5. Turn off the fuel supply to the engine.
  6. Disconnect the battery negative cable first using an insulated wrench.
  7. Place warning notices at each location.

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 is the displacement of the Cummins/Onan B3.3G2?

The Cummins/Onan B3.3G2 has a displacement of 3.3 liters.

Which generators use the Cummins/Onan B3.3G2 engine?

The Cummins/Onan B3.3G2 powers 3 generator set(s), including Cummins/Onan B3.3-G2, Cummins/Onan C50 D6, Cummins/Onan C55 D5.

What is a common problem with the Cummins/Onan B3.3G2 engine?

A commonly reported issue on generators using the Cummins/Onan B3.3G2 is: Weakness and Sleepiness. Fix: IF YOU OR ANYONE ELSE EXPERIENCEANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired..