HomeEnginesGeneral Motors Vortec 4.3L

General Motors Vortec 4.3L Engine

The General Motors Vortec 4.3L is a 4.3 L 6-cylinder natural aspiration engine rated at 1800 rpm, producing up to 56 kW. It powers generator sets from Kohler, SDMO and Winco, including the 30RZG, 35RZ, 38RCL and 40ERES. It holds 4.3 L (1.1 gal) of oil and 15 L (4.0 gal) of coolant.

Also known as: General Motors Vortec 4.3L

4.3 L
Displacement
6
Cylinders
1800 rpm
Rated speed
56 kW
Gross power

Engine specifications

Oil capacity4.3 L
Coolant capacity15.0 L
Displacement4.3 L
Cylinders6
AspirationNatural Aspiration
Rated speed1800 rpm
Gross power56 kW

Common problems

15
  • The generator set does not crank.
    Cause: Battery weak or dead, Battery connections reversed or poor, Blown fuse(s)
    Fix: Recharge or replace the battery, Check the connections, Replace the fuse. Contact an authorized Kohler distributor/dealer for service if fuse blows repeatedly
  • The generator set cranks but does not start, starts hard, lacks power, or operates erratically.
    Cause: Air cleaner clogged, Battery weak or dead, Battery connection poor, Spark plug wire connection loose, Low oil pressure shutdown, Fuel pressure insufficient, Engine fuse blown, Engine malfunction
    Fix: Clean and/or replace the air cleaner, Recharge or replace the battery, Clean and tighten the battery connections, Check the spark plug wires, Check for oil leaks. Check the oil level and add oil if necessary, Check the fuel supply and valves, Replace the fuse. If the fuse blows again, contact an authorized Kohler distributor/dealer, Contact an authorized Kohler distributor/dealer
  • No AC output.
    Cause: AC circuit breaker in the OFF position, AC circuit breaker tripping because of overload, AC circuit breaker tripping because of short circuit
    Fix: Place the circuit breaker in the ON position, Reduce the load on the generator set, Contact an authorized Kohler distributor/dealer for service
  • Low output or excessive drop in voltage.
    Cause: Generator set overloaded
    Fix: Reduce the load
  • LCM relays do not operate.
    Cause: Bad connections.
    Fix: Check wiring and connections. Verify that cable size and length of run comply with the instructions in the Installation manual. Low or no battery voltage. Check battery connections.
  • Generator set stops suddenly.
    Cause: Low oil pressure shutdown, Out of fuel, Overcrank shutdown
    Fix: Check for oil leaks. Check the oil level and add oil if necessary, Check fuel supply, Reset the controller. If the overcrank fault occurs again, contact an authorized Kohler distributor/dealer
  • Generator set is OFF.
    Fix: Press the RUN button to start the engine or press AUTO to allow remote starting
  • Date is flashing.
    Cause: Controller power was disconnected and then reconnected.
    Fix: Check battery connections. See Figure 5-1. Check utility power connection for the built-in battery charger. Reset the time, date, and exercise schedule. See Section 2.5.7, Setting the Exerciser at Power-Up.
  • Controller LCD display is off.
    Cause: Low or no battery voltage.
    Fix: Check connections. Check generator set battery. See Figure 5-1.
  • Controller display backlight is off.
    Cause: Backlight turns off after about 1 minute with no activity.
    Fix: Backlight will turn on when a button is pressed or the generator set starts. Loss of communication to accessory modules: Bad connections. Check wiring and connections. Verify that cable size and length of run comply with the instructions in the Installation manual. Low or no battery voltage. Check battery connections.
  • Vibration
    Cause: - The vibration is engine-speed related. - The vibration may be sensitive to accessory load.
    Fix: 1. Verify that the vibration is engine related. 2. Inspect the engine cooling fan for bent, twisted, loose or cracked blades. 3. Inspect the fan clutch for smoothness, ease of turning. 4. Inspect for a bent fan shaft or bent mounting flange. 5. Accessory drive component brackets that are bent, cracked or loose may put extra strain on that accessory component causing it to vibrate.
  • The noise occurs when a heavy load is applied to the drive belt
    Cause: An overcharged A/C system, power steering system with a pinched hose or wrong fluid or a generator failing are suggested items to inspect.
  • Rumbling noise
    Cause: - Pilling, the accumulation of rubber dust that forms small balls (pills) or strings in the drive belt pulley groove - The separation of the drive belt - A damaged drive belt
    Fix: 1. Remove the drive belt(s). 2. Operate the engine for no longer than 30 to 40 seconds. 3. Does the rumbling noise still exist? 4. Inspect the drive belt(s) for damage, separation or sections of missing ribs. 5. Clean the drive belt pulleys using a suitable wire brush. 6. Reinstall the drive belt. Refer to Drive Belt Replacement. 7. Install a new drive belt. Refer to Drive Belt Replacement.
  • A loud screeching noise that is caused by a slipping drive belt
    Cause: A slipping drive belt (this is unusual for a drive belt with multiple ribs)
    Fix: Test the drive belt tensioner for proper operation. Inspect for an accessory drive component seized bearing or faulty accessory drive component.
  • A high pitched continuous noise that may be caused by an accessory drive component failed bearing
    Fix: Inspect for a failed accessory drive component. Test the drive belt tensioner for proper operation. Inspect for the correct drive belt length. Inspect for a misalignment of a pulley. Inspect for the correct pulley size.

Compiled from service & troubleshooting documentation across every generator set that uses the General Motors Vortec 4.3L.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filter4.3L1000 hr
Fuel filter4.3L1000 hr
Oil filterFilter, oilGM28351 Amazon $25.85 eBay $19.46
Battery12VDC1000 hr
BeltSerpentine belt system with spring-loaded tensionerGM16132 Amazon eBay $86.00
Coolant4.3L6.8 L1000 hr
Oil4.3L5.7 L1000 hr
Spark plugSpark plugGM16531 Amazon eBay $8.08

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

Service intervals

10
ItemActionHoursMonthsNotes
Engine oil levelCheck24 hrCheck the oil level in the crankcase every 24 hours of operation or before the engine is started each day
Air cleaner elementInspect100 hr
Change engine oil and filterChange100 hr
Check all bolts and nuts for tightnessCheck100 hr
Air cleaner elementReplace1000 hr
Belts and belt tensionCheck1000 hr
Engine coolantReplace5000 hr60 moWhen long-life coolant used
Check coolant levelCheck0 mo
Check engine oil levelCheck0 mo
Check for fluid leaksCheck0 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

42
TypeItemValueUnitCondition
GapSpark plug gap0.51mm (0.02 in.)
GapSpark plug gap0.7--0.8mm (0.028--0.030 in.)
GapSpark plug gap0.76mm (0.03 in.)
GapSpark plug gap0.8--0.9mm (0.03--0.04 in.)
GapSpark plug gap0.89mm (0.035 in.)
GapSpark plug gap0.9--1.0mm (0.036--0.04 in.)
Other10 in. weld flange bolt circle diameter B361.95mm (14.25 in.)
Other10 in. weld flange outside diameter C406.4mm (16.0 in.)
Other10 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other12 in. weld flange bolt circle diameter B431.80mm (17.00 in.)
Other12 in. weld flange outside diameter C482.6mm (19.0 in.)
Other12 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other14 in. weld flange bolt circle diameter B476.25mm (18.75 in.)
Other14 in. weld flange outside diameter C533.4mm (21.0 in.)
Other14 in. weld flange quantity of bolts / bolt hole diameter D12, 28.58mm (1.13 in.)
Other16 in. weld flange bolt circle diameter B539.75mm (21.25 in.)
Other16 in. weld flange outside diameter C596.9mm (23.5 in.)
Other16 in. weld flange quantity of bolts / bolt hole diameter D16, 28.58mm (1.13 in.)
Other18 in. weld flange bolt circle diameter B577.85mm (22.75 in.)
Other18 in. weld flange outside diameter C635.0mm (25.0 in.)
Other18 in. weld flange quantity of bolts / bolt hole diameter D16, 31.75mm (1.25 in.)
Other20 in. weld flange bolt circle diameter B635.00mm (25.00 in.)
Other20 in. weld flange outside diameter C698.5mm (27.5 in.)
Other20 in. weld flange quantity of bolts / bolt hole diameter D20, 31.75mm (1.25 in.)
Other5 in. weld flange bolt circle diameter B215.90mm (8.50 in.)
Other5 in. weld flange outside diameter C241.30mm (9.50 in.)
Other5 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other6 in. weld flange bolt circle diameter B254.0mm (10.0 in.)
Other6 in. weld flange outside diameter C279.4mm (11.0 in.)
Other6 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other8 in. weld flange bolt circle diameter B298.45mm (11.75 in.)
Other8 in. weld flange outside diameter C342.9mm (13.5 in.)
Other8 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
OtherWeld flange angle A (10, 12, 14 in. nominal pipe size)30deg.
OtherWeld flange angle A (16, 18, 20 in. nominal pipe size)22.5deg.
OtherWeld flange angle A (5, 6, 8 in. nominal pipe size)45deg.
TemperatureBlock heater thermostat cut-off temperature27--38°Ccoolant temperature
TemperatureBlock heater thermostat cut-off temperature80--100°Fcoolant temperature
TorqueSpark plug torque15Nm (11 ft. lb.)
TorqueSpark plug torque18Nm (13.3 ft. lb.)
TorqueSpark plug torque24.4--29.8Nm (18--22 ft. lb.)
TorqueSpark plug torque25Nm (18 ft. lb.)

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% ethylene glycol0.6 LProvides freezing protection to --37_C (--34_F) and overheating protection to 129_C (265_F). Do not use alcohol or methanol antifreeze. Coolant added after block heater installation is approximately 0.6 L (0.2 gal).
CoolantLong-life coolantChange interval 5000 hours or 5 years when long-life coolant used; do not mix coolant types
Engine oilSAE 5W-30API Starburst (for gasoline engines)below -18°C4.7 LFor below -18C (0F)
Engine oilSAE 10W-30API Starburst (for gasoline engines)above -18°C4.7 LFor -18C (0F) and above; CC/CD classification and straight-weight industrial/stationary oils not acceptable

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

27
CodeNameMeaningSeverityAction
AC Sens LostAC Sensing LostIn Auto mode, generator output AC sensing is lost; starts 10 seconds after crank disconnect. Warning after 1 second if no output detected after crank disconnect; shutdown after 3 seconds if voltage was present and then lost.WarningContact an authorized distributor/dealer for service.
ATS Com ErrorATS Communication ErrorWarning is displayed if RXT interface connection is lost.WarningCheck communication wiring between transfer switch interface board and generator set.
ATS PhaseRotATS Phase Rotation MismatchTransfer switch phase rotation does not match; ATS will not transfer.WarningCorrect the ATS connection per the ATS Installation manual, wiring diagrams, and labels on the transfer switch.
Accy PwrOverAccessory Power OverloadOver current fault on the accessory controller power outputWarning
Accy PwrOver WarningAccessory Power OverloadAn over current fault (short circuit) on the accessory controller power output.WarningContact an authorized distributor/dealer for service.
Alt Protect ShtdwnAlternator Protection ShutdownHigh generator current detected; shuts down to protect alternator windings from overheating (38RCL only).ShutdownReduce the load.
Aux InputAuxiliary InputAn optional customer-connected input is closed (digital input from optional PIM).ShutdownCheck customer-supplied equipment.
Batt Chg FltBattery Charger FaultInput to PIM from an external battery charger (not the built-in charger).WarningCheck external battery charger.
Battery Voltage HighBattery Voltage HighEngine starting battery voltage rises above 125% of the battery voltage setting for more than 10 seconds; inhibited during crank cycle.WarningCheck the battery rating and condition; check the battery charger operation.
Battery Voltage LowBattery Voltage LowEngine starting battery voltage falls below the battery voltage setting (typically 12.5 volts) for more than 90 seconds when engine not running; inhibited during crank cycle.WarningCheck the battery rating and condition; check the battery charger operation; charge or replace the battery.
CAN comm faultCAN Communications FaultEngine CAN communications fault.ShutdownCheck wiring to ECM; check power to ECM.
Engine Coolant Temperature HighEngine Coolant Temperature HighEngine coolant temperature exceeds the maximum temperature for more than 5 seconds; active after crank disconnect.ShutdownCheck for blocked air inlets and exhaust outlets.
Engine Oil Pressure LowEngine Oil Pressure LowThe engine ECM indicates low oil pressure for more than 5 secondsShutdownCheck for leaks in the lubrication system; check the oil level and add oil if low.
EngineSpeed HighEngine Speed HighEngine speed exceeds 115% of normal running speed for more than 0.3 seconds.ShutdownContact an authorized distributor/dealer for service.
EngineSpeed LowEngine Speed LowEngine speed drops below 85% of normal running speed for more than 3 seconds.ShutdownReduce the load; contact an authorized distributor/dealer for service.
Exer Not SchExercise Not ScheduledNo exercise has been scheduled on the RDC2 controller.WarningSee exerciser setup instructions.
Generator Frequency HighGenerator Frequency HighGoverned frequency exceeds 110% of the system's frequency setpoint for more than 10 seconds; active 10 seconds after engine start.ShutdownContact an authorized distributor/dealer for service.
Generator Frequency LowGenerator Frequency LowGoverned frequency falls below 90% of system frequency setting for more than 10 seconds, or 1 Hz below setting for more than 60 seconds; active 10 seconds after engine start.ShutdownReduce the load and restart the generator set; contact an authorized distributor/dealer for service.
Generator VoltageL1-L2 HighGenerator Voltage HighOutput voltage exceeds 120% of the system nominal voltage for more than 2 seconds.ShutdownContact an authorized distributor/dealer for service.
Generator VoltageL1-L2 LowGenerator Voltage LowOutput voltage falls below 80% of the nominal system voltage for more than 10 seconds.ShutdownReduce the load and restart the generator set; contact an authorized distributor/dealer for service.
Lo Crank VltLow Cranking VoltageBattery voltage falls below 60% of system battery voltage for more than 6 seconds while the starter is engaged.WarningCharge or replace the battery.
Locked RotorLocked RotorNo engine rotation is sensed during cranking; shuts down 3 seconds after the fault is detected.ShutdownCheck the battery; check for loose connections; contact an authorized distributor/dealer for service.
MainPwrOverL ShutdownMain Power OverloadAn over current fault on the controller power output (short circuit).ShutdownContact an authorized distributor/dealer for service.
Not in AutoNot in Automatic ModeThe generator set is not in Automatic (standby) mode; remote start/stop commands from a transfer switch or remote switch will be ignored.WarningPress AUTO to place the generator set in Automatic mode, when appropriate.
Over CrankOver CrankThree unsuccessful starting attempts.ShutdownCheck the fuel supply, spark plug, and battery; check for loose connections; contact an authorized distributor/dealer for service.
Speed Sensor FaultSpeed Sensor FaultEngine speed sensor has failed or engine stalled.ShutdownContact an authorized distributor/dealer for service.
Total Power High ShtDwnTotal Power High ShutdownMeasured load is greater than 102% of the generator set power rating for more than 1 minute (38RCL only).ShutdownReduce the load.

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
RDC2 Voltage Calibration Using SiteTech adjustment

Tools: digital voltmeter, personal computer, SiteTech software

  1. Connect PC to controller via USB
  2. With generator off, connect multimeter across L1/L2 (AC volts)
  3. Start generator set
  4. Compare voltmeter reading to controller display
  5. Calculate new Genset Calibration Factor Voltage using (Vmeter / Vcontrol) x Fold = Fnew
  6. Enter new value into SiteTech and click Apply Changes
  7. Verify voltmeter matches controller display
  8. Repeat for L2-L3 and L3-L1 if three-phase
  9. Press OFF to stop generator set
RDC2 Voltage Calibration Using the Controller Keypad adjustment

Tools: digital voltmeter

  1. With generator off, connect digital multimeter across L1 and L2, set to AC volts
  2. Start generator set with RUN button
  3. Navigate to Generator Metering menu, press Select; Volts L1-L2 displayed
  4. Press Select; voltage number flashes
  5. Use up/down arrows to match voltmeter reading
  6. Press Select to confirm
  7. Step to Return screen
  8. Press OFF to stop generator set
VSC Current (Load) Calibration Using the Controller Keypad adjustment

Tools: clamp-on DC current probe or DC current meter

  1. Connect DC current probe/clamp meter to measure generator current
  2. Start generator with RUN button
  3. Adjust system voltage to obtain rated current output with battery bank attached (or use load bank)
  4. Trip output breaker
  5. Navigate to Generator Metering menu, select Generator Load
  6. Press and hold Select for No-Load Calibration; verify breaker open, confirm Yes
  7. Close output breaker; verify rated output current, confirm Yes
  8. Verify displayed load is correct; recalibrate if necessary
  9. Press OFF to stop generator set
Procedure to Reset the Controller after a Fault Shutdown diagnostic

⚠ Always identify and correct the cause of a fault shutdown before resetting the controller.

  1. Press the Select button to go to the Overview menu.
  2. Press Select again to display the active fault.
  3. Press Select; Confirm Clear Fault: NO is displayed.
  4. Press the Up arrow button; Confirm Clear Fault: YES is displayed.
  5. Press the Select button to enter YES and clear the fault.
  6. Press the Select button to return to the overview menu.
  7. Press AUTO to put the generator set into automatic mode.
Install the block heater installation

⚠ Block heater damage. The block heater will fail if the energized heater element is not immersed in coolant. Fill the cooling system before turning on the block heater.

⚠ Do not add coolant to a hot engine. Wait until the engine has cooled.

⚠ Hot coolant and steam. Stop the generator set and allow it to cool before removing the pressure cap.

Tools: pipe sealant, cable tie

  1. Secure the block heater to the block heater mounting bracket (GM78546) using 4 screws (M933-06020-60), 4 washers (M125A-06-80), and 4 hex nuts (M6923-06-80).
  2. Secure the mounting bracket with block heater to the skid using 2 screws (M933-06016-60) and 2 hex nuts (M6923-06-80).
  3. Locate the 2 shutoff valves on opposite sides of the engine block and verify they are closed.
  4. Remove the pipe plug from each shutoff valve and discard the plugs.
  5. Apply pipe sealant to the threads of hose connectors X-391-19 and X-582-1.
  6. Install the 90 degree hose connector (X-391-19) in the shutoff valve closest to the block heater.
  7. Install the straight connector (X-582-1) in the shutoff valve on the opposite side of the engine.
  8. Hold the molded hose (276206 or GM103656) in place and cut to fit if necessary.
  9. Install the shorter heat shield (GM17809) over the molded hose and secure with a cable tie.
  10. Connect the molded hose to the hose connector and secure with a hose clamp (X-426-12 or GM103203).
  11. Connect the other end of the hose to the block heater outlet and secure with a hose clamp (X-426-12 or GM103203).
  12. Install the longer heat shield (GM23718) over the inlet hose (X-312-53 or X-312-47) and secure with a cable tie.
  13. Connect the hose to the block heater inlet with a hose clamp (X-426-12); route the hose under the engine.
  14. Secure the hang tag (279047) to the power cord.
  15. Open the two block heater shutoff valves and, after the block heater is full, add approximately 0.6 L (0.2 gal) coolant to the cooling system.
Air Cleaner Element and Precleaner maintenance
  1. Disable set: press OFF button, disconnect battery charger power, remove battery cables, negative (--) lead first.
  2. Loosen the cover retaining knob(s) or release the retaining clips and remove the cover.
  3. Remove and discard the old air cleaner element and precleaner (if equipped).
  4. Install the precleaner over the new air cleaner element.
  5. Install the paper element onto the air cleaner base, making sure it is flat and properly seated.
  6. Reinstall the element cover, element cover nut, and the air cleaner cover; secure with the knob(s) or clips.
  7. 15RES/30RES and RCL models: wipe cover and housing with a clean rag and make sure sealing surfaces fit correctly.
  8. Reconnect the battery cable, negative (--) lead last.
Air Cleaner Service Procedure maintenance

⚠ Do not clean the element in any liquid or use compressed air; this will damage the filter element.

  1. Remove the cover from the air cleaner housing.
  2. Remove the air cleaner element.
  3. Examine the element and housing for damage; replace if damaged.
  4. Tap the element lightly against a flat surface to dislodge loose surface dirt.
  5. Wipe the cover and housing with a clean rag to remove dirt.
  6. Replace the air cleaner cover.
Firmware Update Using SiteTech maintenance

⚠ Do not load RDC2.4 firmware onto a red- or green-board controller

Tools: personal computer, USB cable, SiteTech software

  1. Download latest firmware file (.bin) from Kohler Power Resource Center or dealer portal
  2. Connect controller to PC via USB cable
  3. Start SiteTech; program recognizes connected device
  4. Click Update Firmware
  5. Browse to and select firmware file, click Open
  6. Verify current/new version and file name, click Update Firmware
  7. Wait for 'Firmware Updated Successfully' message, click Close
Oil and Filter Change maintenance

⚠ Dispose of waste materials (oil, fuel, filter) in an environmentally safe manner.

Tools: oil filter wrench, drain hose

  1. Press the OFF button on the RDC2 generator set controller.
  2. Disconnect the power for the battery charger.
  3. Disconnect the generator set engine starting battery, negative lead first.
  4. Remove the housing side panel.
  5. Remove the plug from the oil drain fitting and install a drain hose.
  6. Open the oil drain valve on the engine and allow oil to drain completely.
  7. Close the oil drain valve and replace the oil drain plug.
  8. Remove the oil filter by rotating counterclockwise with an oil filter wrench.
  9. Clean the contact surface of the oil filter adapter; apply light coat of clean oil to new filter's rubber seal.
  10. Install the new oil filter.
  11. Fill with oil per oil selection chart and capacity (4.7 L / 5.0 qt).
  12. Reconnect the battery negative lead last and reconnect battery charger power.
  13. Start the generator set and check for leaks around the oil filter; tighten if necessary.
  14. Stop the generator set, check oil level, and add oil to bring to the Full mark.
  15. Reset the maintenance timer on the RDC2 controller.
Oil and Oil Filter maintenance

⚠ Hot engine oil can cause severe injury or death. Avoid skin contact with hot oil.

⚠ Do not work on the generator set until it cools.

⚠ Accidental starting can cause severe injury or death. Remove the negative (--) lead first when disconnecting the battery.

Tools: Funnel, Drain tube (3/8 in. inside diameter), Catch basin / drain pan

  1. Disable set: press OFF button, disconnect battery charger power, remove battery cables, negative (--) lead first.
  2. Drain the oil while it is warm. On most models a drain plug is on the service side, opposite the starter.
  3. For most models remove one oil drain plug and the oil fill cap/dipstick; aim the drain tube into a catch basin.
  4. For most models open the valve near the oil sump and allow ample time for complete drainage.
  5. Close the valve and place the tube back in the clip on the bulkhead wall.
  6. For 8/10/12RESV(L), cover the alternator with rags near the oil drain valve and oil filter.
  7. For 8/10/12RESV(L), place a drain tube (3/8 in. inside diameter) onto the oil drain valve into a drain pan.
  8. For 8/10/12RESV(L), open the oil drain valve, remove the dipstick and oil fill cap, and drain completely.
  9. For 8/10/12RESV(L), close the oil drain valve and remove the oil drain tube.
  10. Remove the old filter, tilting it upward to prevent spilling, and wipe off the adapter/base on the engine.
  11. Place a new replacement filter open end up in a shallow pan; pour new oil (provided) through the threaded center hole to the bottom of threads.
  12. Allow a minute or two for the oil to be absorbed by the filter material.
  13. Apply a thin film of clean oil to the rubber gasket on the new oil filter.
  14. Install the new oil filter; hand tighten clockwise until the gasket contacts the adapter, then tighten an additional 3/4--1 turn.
  15. Fill the crankcase with new oil to the F/FULL mark on the dipstick; reinstall cap/dipstick, reconnect battery cable negative (--) lead last, test run, check for leaks, and recheck oil level.
Remove the generator set from service maintenance

⚠ Disconnect the battery cables before working on the generator set. Remove the negative (--) lead first when disconnecting and reconnect it last.

  1. Press the OFF button on the generator set controller.
  2. Disconnect the utility power to the generator set.
  3. Disconnect the generator set engine starting battery, negative (--) lead first.
Spark Plugs maintenance

⚠ Servicing the air cleaner: a sudden backfire can cause severe injury. Do not operate with the air cleaner removed.

Tools: 13/16 in. socket, 5/8 in. spark plug socket, Wire feeler gauge, Torque wrench

  1. Disable set: press OFF button, disconnect battery charger power, remove battery cables, negative (--) lead first.
  2. Clean or blow out the area around the base of the plug(s) before removal to keep dirt out of the engine; wear eye protection.
  3. Using a spark plug socket, remove and discard the old spark plug(s).
  4. 24RCL, 30RCL, and 38RCLB: use a 13/16 in. socket. Other models: use a 5/8 in. spark plug socket.
  5. Check and set the gap of the new spark plug(s) using a wire feeler gauge.
  6. Adjust the gap by carefully bending the ground electrode.
  7. Apply a light coating of anti-seize lubricant to the spark plug threads and wipe away any excess compound.
  8. Install the new spark plug(s) and torque as shown in Figure 4.
  9. Reconnect the spark plug lead(s).
  10. Reconnect the battery cable, negative (--) lead last.

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

VoltagePhaseConnectionLeadsNotes
12-LeadAlternator Reconnections diagram ADV-5875B-M (page 16)
4-LeadAlternator Reconnections diagram ADV-5875A-M (page 15)
Alternator Reconnection drawing ADV-5875U--144--Lead
100/2001Single
100/2003Delta
110/2201Single
110/2203Delta
115/2301Single
1201SingleGenset System Voltage/Frequency/Phase table for controller setup
120/2083Wye
120/2401Single
120/2403Delta
127/2203Wye
2201Single
220/3803Wye
2301Single
230/4003Wye
2401Single
240/4163Wye
277/4803Wye

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 oil capacity of the General Motors Vortec 4.3L?

The General Motors Vortec 4.3L engine has an oil capacity of 4.3 liters.

What is the displacement of the General Motors Vortec 4.3L?

The General Motors Vortec 4.3L has a displacement of 4.3 liters with 6 cylinders.

Which generators use the General Motors Vortec 4.3L engine?

The General Motors Vortec 4.3L powers 13 generator set(s), including Kohler 30RZG, Kohler 35RZ, Kohler 38RCL, Kohler 40ERES, Kohler 40REZG.

How often should you change the oil in the General Motors Vortec 4.3L?

The General Motors Vortec 4.3L oil change interval is every 1000 hours.

What is a common problem with the General Motors Vortec 4.3L engine?

A commonly reported issue on generators using the General Motors Vortec 4.3L is: The generator set does not crank.. Cause: Battery weak or dead, Battery connections reversed or poor, Blown fuse(s). Fix: Recharge or replace the battery, Check the connections, Replace the fuse. Contact an authorized Kohler distributor/dealer for service if fuse blows repeatedly.