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Kohler 8RESV Engine

The Kohler 8RESV is an engine rated at 3600 rpm. It powers generator sets from Kohler. It holds 1.5 L (0.4 gal) of oil.

Also known as: Kohler 8RESV engine

3600 rpm
Rated speed
1.5 L
Oil capacity

Engine specifications

Oil capacity1.5 L
Rated speed3600 rpm

Troubleshooting

8

Symptoms & remedies

SymptomCauseRemedy
Controller display backlight is off.Backlight turns off after about 1 minute with no activity.Backlight will turn on when a button is pressed or the generator set starts.
Controller display is off.Low or no battery voltage.Check connections. Check generator set battery.
The generator set does not crank.Battery weak or dead.Recharge or replace the battery.
Fault shutdown.Check the controller display for fault messages. See Section 2.5. Correct the fault condition and reset the controller.
Generator set in the OFF mode.Press the RUN button to start the engine or press AUTO to allow remote starting.
Gererator thermostat tripped.For trips other than temperature (nuisance trips),Reset the thermostat. See Section 2.6.
The generator set cranks but does not start, starts hard, lacks power, or operates erratically.Air cleaner clogged.Clean and/or replace the air cleaner.
ExplosionFuel system leakageCheck LPG vapor or natural gas fuel system for leakage by using a soap and water solution with the fuel system test pressurized to 6-8 ounces per square inch (10-14 inches water column).

Fault codes and symptom→remedy steps extracted from this engine’s service/owner documentation; verify against the official manual before servicing.

Common problems

8
  • The generator set does not crank.
    Cause: Battery weak or dead.
    Fix: Recharge or replace the battery.
  • The generator set cranks but does not start, starts hard, lacks power, or operates erratically.
    Cause: Air cleaner clogged.
    Fix: Clean and/or replace the air cleaner.
  • Gererator thermostat tripped.
    Cause: For trips other than temperature (nuisance trips),
    Fix: Reset the thermostat. See Section 2.6.
  • Generator set in the OFF mode.
    Fix: Press the RUN button to start the engine or press AUTO to allow remote starting.
  • Fault shutdown.
    Fix: Check the controller display for fault messages. See Section 2.5. Correct the fault condition and reset the controller.
  • Explosion
    Cause: Fuel system leakage
    Fix: Check LPG vapor or natural gas fuel system for leakage by using a soap and water solution with the fuel system test pressurized to 6-8 ounces per square inch (10-14 inches water column).
  • Controller display is off.
    Cause: Low or no battery voltage.
    Fix: Check connections. Check generator set battery.
  • 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.

Compiled from service & troubleshooting documentation across every generator set that uses the Kohler 8RESV.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterPaper element replacement150 hr
Fuel filterCheck flexible lines and connections
Oil filter100 hr
Oil5W-30 API SG/SH/SJ synthetic1.5 L100 hr
Spark plugGap 0.508 mm (0.020 in.)500 hr

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

Service intervals

18
ItemActionHoursMonthsNotes
Oil levelCheck8 hrBefore each use and every 8 hours
engine oil levelCheck8 hrCheck before each use; for extended operation check every 8 hours
OilChange100 hr12 moYearly or 100 hours
Oil filterReplace100 hr12 moYearly or 100 hours
Valve lash (8RESV/L)Adjust100 hr100 hours
valve lash (8RESV)Check100 hr8RESV models only; requires authorized service
Air cleanerReplace150 hr12 moYearly or 150 hours
air cleanerOther150 hr12 moService more frequently under dusty conditions
engine oil and filterChange400 hr12 moUse 5W-30 synthetic oil
Crankcase breather hoseClean500 hr12 moYearly or 500 hours
Spark plugsReplace500 hr12 moYearly or 500 hours
Stepper motor coupling and bushingReplace500 hr500 hours
Valve lash (10/12RESV/L)Adjust500 hr500 hours
valve lash (10/12RESV)Check500 hr10/12RESV models only; requires authorized service
Battery cleaner operationCheck1 moMonthly
Battery electrolyte levelCheck12 moYearly
Fuel flexible linesInspect3 moQuarterly
batteryCheck1 moMonthly for first year; annually thereafter

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

18
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.)
PressureLPG fuel supply1.7-2.7kPa
PressureNatural gas fuel supply0.87-2.7kPa
Spark plug gapSpark plug gap0.508mmAll models
TemperatureCarburetor heater thermostat OFF16 ± 3C (60 ± 5F)
TemperatureCarburetor heater thermostat ON4 ± 4C (40 ± 7F)
TemperatureThermostat OFF16 ± 3°CThermostat OFF (60 ± 5°F)
TemperatureThermostat ON4 ± 4°CThermostat ON (40 ± 7°F)
TorqueSpark plug installation torque24.4 - 29.8NmInstallation
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
Engine oil5W-30API Service Class SG, SH, or SJ syntheticSynthetic oil oxidizes and thickens less; recommended for cleaner intake valves and pistons
Engine oil5W-30 API SG/SH/SJ syntheticAPI SG/SH/SJSynthetic oil recommended
FuelGasolineUnleaded gasolineLP or natural gas capable

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
Install Carburetor Heater, 17/18/20 kW Models installation

⚠ Accidental starting can cause severe injury or death; disconnect battery cables before working on the generator set, negative lead first.

⚠ Hazardous voltage will cause severe injury or death; disconnect all power sources before opening the enclosure.

⚠ Hot surfaces: disconnect power to the heater and allow it to cool before servicing.

  1. Open enclosure roof; locate controller and air cleaner.
  2. Turn off the generator set (master switch or controller OFF button, per model).
  3. Disconnect AC power to the generator set at the distribution panel breaker.
  4. Disconnect the starting battery, negative lead first.
  5. Check nameplate model/spec number and locate heater position per Figure 4.
  6. Remove the air cleaner cover if needed for access.
  7. Disconnect the heating element from the power cord at the plug connector.
  8. Insert the heating element into the threaded opening on the engine and tighten.
  9. Reconnect the power cord to the heater.
  10. Route and connect the power cord per the applicable model wiring option (steps 10-12).
  11. Replace the air cleaner cover if it was removed.
  12. Affix decal GM22387 onto the air cleaner cover.
  13. Reconnect the starting battery, negative lead last.
  14. Reconnect AC power by closing the distribution panel breaker.
  15. For standby operation, move switch to AUTO and reinstall enclosure panels.
Install Carburetor Heater, Models 8-12RESV/RESVL installation

⚠ Accidental starting can cause severe injury or death; disconnect battery cables before working on the generator set, negative lead first.

⚠ Hazardous voltage will cause severe injury or death; disconnect all power sources before opening the enclosure.

⚠ Hot surfaces: install the heater before connecting it to power; disconnect power and allow it to cool before servicing.

  1. Open the enclosure roof.
  2. Press the OFF button on the generator set controller.
  3. Disconnect AC power to the generator set at the distribution panel breaker.
  4. Disconnect the starting battery, negative lead first.
  5. Locate the carburetor heater per Figure 14; remove side panel or air cleaner cover if needed.
  6. Remove and discard the M8 bolt from the carburetor at the heater location.
  7. Thread adapter GM91361 into the M8 hole.
  8. Insert carburetor heater GM57968 into the adapter and tighten.
  9. Connect the extension cord (GM91360 or 3-way GM95628) to the heater cord.
  10. Route the cord to the AC receptacle, securing away from throttle linkage and exhaust.
  11. Plug the cord into the AC receptacle on the generator bulkhead.
  12. Affix decal GM22387 onto the air cleaner cover.
  13. Reconnect the starting battery, negative lead last.
  14. Reconnect AC power by closing the distribution panel breaker.
  15. Press AUTO for standby operation and reinstall enclosure panels.
Installation Procedure, 17/18/20 kW Models installation

⚠ Disconnect battery cables before working on generator set; remove negative lead first.

⚠ Disconnect all power sources before opening enclosure.

⚠ Install heater before connecting power; allow to cool before servicing.

  1. Open enclosure roof; locate controller and engine air cleaner.
  2. Turn off generator set: 17/18RES/RESL move master switch OFF; 20RES/RESL press OFF and remove fuse F3; 20RESA/AL/B/C/CL/D press OFF.
  3. Disconnect AC power by opening circuit breaker in distribution panel.
  4. Disconnect engine starting battery, negative lead first.
  5. Check nameplate model/spec; see Figure 4 for heater location. Heater fits threaded opening on carburetor below air cleaner.
  6. Remove air cleaner cover if easier access needed.
  7. Disconnect heater element from power cord at plug connector (GM57968 or GM88228).
  8. Insert heating element into threaded opening on engine and tighten.
  9. Reconnect power cord to heater.
  10. For 17/18RES/RESL and 20RES/RESL: remove air intake panel; install bushing X-634-15 or X-634-16; route cord through bulkhead; plug into 120 VAC receptacle under controller.
  11. For 120 V 20RESA/AL/B/C/CL/D: route cord away from hot parts; plug into receptacle in engine compartment; use 3-way cord GM95628 if multiple accessories; secure excess cable.
  12. For 240 V 14/20RESA and 20RESC: remove controller screws, remove bulkhead knockout, route cord and insert plug; disconnect 120 VAC harness at 3-pin; connect 3-pin to new 240 VAC connector.
  13. Replace air cleaner cover if removed; affix decal GM22387 as shown.
  14. Check master switch OFF (17/18); reconnect battery, negative last; close distribution breaker. 20RES/RESL: reinstall fuse F3.
  15. For standby, move master switch to AUTO or press AUTO. Reinstall enclosure panels; close and lock roof.
Installation Procedure, Models 8-12RESV/RESVL installation

⚠ Disconnect battery cables before working on generator set; remove negative lead first.

⚠ Disconnect all power sources before opening enclosure.

⚠ Install heater before connecting power; allow to cool before servicing.

  1. Open enclosure roof.
  2. Press OFF button on generator set controller.
  3. Disconnect AC power by opening circuit breaker in distribution panel.
  4. Disconnect engine starting battery, negative lead first.
  5. See Figure 13 for heater location. Remove louvered side panel and/or air cleaner cover for access if necessary.
  6. Remove and discard M8 bolt from carburetor at heater location.
  7. Thread adapter GM91361 into M8 hole.
  8. Insert carburetor heater GM57968 into adapter and tighten.
  9. Connect extension cord GM91360 or 3-way extension cord GM95628 to heater cord.
  10. Route cord to AC receptacle as shown; secure with cable ties away from throttle linkage and exhaust.
  11. Plug cord into AC receptacle on generator bulkhead.
  12. Affix decal GM22387 onto air cleaner cover.
  13. Reconnect battery, negative lead last.
  14. Reconnect AC power by closing circuit breaker.
  15. For standby, press AUTO. Reinstall enclosure panels; close and lock roof.
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 (8RESV/RESVL) maintenance

⚠ Do not wash paper element or clean with pressurized air

  1. Press OFF button and disconnect utility power and battery
  2. Loosen cover retaining knobs and remove cover
  3. Remove paper element
  4. Replace element if dirty, bent, or damaged
  5. Check air cleaner base for condition
  6. Check element cover for damage
  7. Reinstall paper element and air cleaner cover
  8. Secure cover with retaining knobs
  9. Reconnect battery and utility power
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 Change Procedure maintenance

⚠ Accidental starting can cause severe injury or death.

⚠ Risk of fire from fuel system.

⚠ Do not smoke near carburetor or fuel system.

Tools: oil filter wrench, funnel, rags, drain pan

  1. Press OFF button to shutdown generator set.
  2. Disconnect utility power to generator set.
  3. Disconnect engine starting battery (negative lead first).
  4. Remove side panel on exhaust side of enclosure.
  5. Clean area around dipstick and oil fill cap.
  6. Cover alternator with rags to prevent oil spillage.
  7. Insert drain tube onto oil drain valve.
  8. Open oil drain valve and allow oil to drain completely.
  9. Close oil drain valve and remove drain tube.
  10. Clean area around oil filter.
  11. Loosen oil filter with wrench and remove carefully.
  12. Clean gasket sealing surface.
  13. Apply light coat of clean oil to new filter seal.
  14. Thread new oil filter by hand until resistance, then 3/4 turn more.
  15. Fill engine with recommended oil to Full mark on dipstick.
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.

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
100/2001Single
100/2003Delta
110/2201Single
110/2203Delta
115/2301Single
1201SingleGenset System Voltage/Frequency/Phase table for controller setup
120/2083Wye
120/2401Single
120/2401Single phase4
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 Kohler 8RESV?

The Kohler 8RESV engine has an oil capacity of 1.5 liters.

Which generators use the Kohler 8RESV engine?

The Kohler 8RESV powers 1 generator set(s), including Kohler 8RESV.

How often should you change the oil in the Kohler 8RESV?

The Kohler 8RESV oil change interval is every 100 hours.

What is a common problem with the Kohler 8RESV engine?

A commonly reported issue on generators using the Kohler 8RESV is: The generator set does not crank.. Cause: Battery weak or dead.. Fix: Recharge or replace the battery..