HomeEnginesHonda GX340 K1

Honda GX340 K1 Engine

The Honda GX340 K1 is a 0.62 L 1-cylinder air-cooled engine rated at 3600 rpm. It powers generator sets from Honda and MQ Power, including the EB5000 and GA-6H. It holds 1.1 L (0.3 gal) of oil.

Also known as: Honda GX340 K1

Part of the Honda GX340 engine family — 2 variants share parts & fitment.

0.625 L
Displacement
1
Cylinders
3600 rpm
Rated speed
1.1 L
Oil capacity

Engine specifications

Oil capacity1.1 L
Displacement0.625 L
Cylinders1
Aspirationair-cooled
Rated speed3600 rpm

Generator sets powered by this engine

2

Shared across brands: Honda, MQ Power

Honda EB5000MQ Power GA-6H

This engine also powers 22 machine(s) on Power Equipment Info.

How to read your Honda engine serial & model number →

Common problems

9
  • Rectifier failure
    Fix: Replace the rectifier
  • Recoil starter malfunction
    Fix: Inspect and repair or replace the recoil starter
  • High fuel consumption, loss of power and excessive carbon buildup in the combustion chamber
    Cause: A clogged air cleaner
    Fix: Cleaning the air cleaner
  • Generator does not start
    Cause: Faulty spark plug
    Fix: Replace the spark plug
  • Fuel cock assembly problem
    Fix: Inspect and repair or replace the fuel cock assembly
  • Engine oil level switch issue
    Fix: Check and replace the oil level switch if necessary
  • Engine breakdowns
    Fix: Follow the diagnosis based on the Engine Troubleshooting information shown below and on the proceeding page. If the problem cannot be remedied, please leave the unit just as it is and consult our company's business office or service plant.
  • Circuit breaker issue
    Fix: Check and replace the circuit breaker if necessary
  • Air filter element problem
    Fix: Clean or replace the air filter element

Compiled from service & troubleshooting documentation across every generator set that uses the Honda GX340 K1.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterService air cleaner.50 hr
Fuel filter200 hr
Oil filterReplace oil filter.50 hr
Battery200 hr
BeltInspect belts for wear, replace as needed.50 hr
Coolant200 hr
Oil4-stroke motor oil that meets or exceeds the requirements for API service classification SJ.1.5 L200 hr
Spark plugReplace spark plugs every 50 hours or as needed.50 hr

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

Service intervals

13
ItemActionHoursMonthsNotes
Engine oilChange300 hr12 moFirst service — First month or 20 Hrs (page 67)
Air cleanerClean50 hr3 moService more frequently when used in dusty areas (1)
Sediment cupClean100 hr6 moPage 58
Fuel tank and filterClean300 hr12 mo(2)
Spark arresterClean300 hr12 moEvery year or 300 Hrs; also must be serviced every 100 hours (page 71)
Spark plugAdjust300 hr12 moCheck-adjust every year or 300 Hrs (page 69)
Spark plugReplace300 hr12 moEvery year or 300 Hrs (page 69)
Valve clearanceAdjust300 hr12 moCheck-adjust every year or 300 Hrs; by servicing dealer (2)
Combustion chamberClean1000 hrAfter every 1,000 Hrs (2)
CanisterCheck24 moEvery 2 years (2)
Charge tubeCheck24 moEvery 2 years (2)
Fuel tubeCheck24 moEvery 2 years (replace if necessary) (2)
Purge tubeCheck24 moEvery 2 years (2)

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

23
TypeItemValueUnitCondition
GapSpark plug electrode gap0.028–0.031 in (0.7–0.8 mm)mm
GapSpark plug gap0.028-0.031in (0.70-0.80 mm)
GapSpark plug gap0.028–0.031in (0.7–0.8 mm)
OtherCompression ratio8.2:1
SpeedEngine speed3,600rpm
SpeedEngine speed protection limit (DAVR self-diagnosis)4140rpmabnormal voltage/speed sustained longer than 3 seconds
TorqueHandle installation17–22 lbf·ft (24–29 N·m, 2.4–3.0 kgf·m)N·m
TorqueHandle installation flange bolts19.5 lbf·ft (26.5 N·m, 2.7 kgf·m)lbf·ft
TorqueHanger kit flange bolts19.5 lbf·ft (26.5 N·m, 2.7 kgf·m)lbf·ft
TorqueHanger kit installation17–22 lbf·ft (24–29 N·m, 2.4–3.0 kgf·m)N·m
TorqueOil drain plug (12×15 mm)16.3 lbf·ft (22.1 N·m, 2.25 kgf·m)lbf·ft
TorqueOil drain plug (12×15 mm)16.6 lbf·ft (22.5 N·m, 2.25 kgf·m)N·m
TorqueSpark plug13.0 lbf·ft (17.7 N·m, 1.8 kgf·m)lbf·ft
TorqueSpark plug13.3 lbf·ft (18 N·m, 1.8 kgf·m)N·m
TorqueWheel kit flange bolts19.5 lbf·ft (26.5 N·m, 2.7 kgf·m)lbf·ft
TorqueWheel kit installation17–22 lbf·ft (24–29 N·m, 2.4–3.0 kgf·m)N·m
Valve clearanceValve clearance EX0.20 ± 0.02mmcold
Valve clearanceValve clearance EX0.20±0.02mmcold
Valve clearanceValve clearance EX0.20±0.02 mmmmcold
Valve clearanceValve clearance IN0.15 ± 0.02mmcold
Valve clearanceValve clearance IN0.15±0.02mmcold
Valve clearanceValve clearance IN0.15±0.02 mmmmcold
VoltageVoltage regulation stability (DAVR)within 1%standard operation

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 oilSAE 10W-30API service category SJ or later (or equivalent)1.1 LMaximum oil capacity 1.2 US qt (1.1 L); 4-stroke automotive detergent oil; other viscosities per ambient temperature chart
Engine oilSAE 10W-30 (other viscosities per ambient temperature chart)API service classification SJ or higher1.1 LNon detergent and 2-stroke oils are not recommended
FuelRegular unleaded gasoline, pump octane rating 86 or higherNo more than 10% ethanol (E10) or 5% methanol by volume23.5 LFuel tank capacity 6.21 US gal (23.5 L)
Fuelunleaded gasoline, pump octane rating 86 or higher17.0 LDo not fill above the shoulder of the fuel strainer; oxygenated fuels allowed up to 10% ethanol, 15% MTBE, 5% methanol by volume

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
GFCI Operation Check (System ①) diagnostic

⚠ A faulty GFCI system will not provide proper protection against electric shock.

⚠ If the GFCI system fails the test, the generator must be repaired by an authorized Honda servicing dealer before use.

  1. Unplug all tools and appliances from the generator.
  2. Start the engine.
  3. Turn OFF the Auto Throttle switch.
  4. Turn the AC circuit breaker to the ON position.
  5. Press the TEST button: the RESET button should pop out and the AC circuit breaker should switch to OFF.
  6. Press the RESET button: it should stay in, flush with its base plate.
  7. With the RESET button in and the engine running, turn the AC circuit breaker to ON; it should remain ON.
GFCI Operation Check (System ②) diagnostic

⚠ If the red indicator starts to blink continuously, contact an authorized Honda generator dealer.

  1. Unplug all tools and appliances from the generator.
  2. Start the engine.
  3. Turn OFF the Auto Throttle switch.
  4. Turn the AC circuit breaker to the ON position; the green indicator should light continuously.
  5. Press the TEST button: the RESET button will pop out and the green indicator will go off.
  6. Press the RESET button: the green indicator will light continuously.
2 Wheel Kit Installation installation
  1. Install the two wheels on the axle shaft.
  2. Install the axle assembly on the generator using four bolts and nuts.
  3. Install the two stands using four bolts and nuts.
  4. Install right and left handles on the generator upper frame using brackets and six bolts.
4 Wheel Kit Installation installation

⚠ Install the shaft with the wheel stopper facing the engine side.

  1. Install the four wheels on the axle shaft.
  2. Install the axle assembly on the generator using four bolts and nuts.
Handle Installation installation

⚠ Do not add fuel or oil before tipping the generator.

Tools: 12 mm wrench (2), pliers

  1. Install the handle holder assembly on the generator upper frame using the 8×18 mm flange bolts.
  2. Install the handle assembly on the upper frame pipe using 8×16 mm flange bolts, handle bush A, handle bush B, and handle lower bracket.
  3. Torque to 19.5 lbf·ft (26.5 N·m, 2.7 kgf·m).
  4. Check that the handle folds smoothly and does not hang down by its own weight.
Hanger Kit Installation installation

Tools: 12 mm wrench (2)

  1. Position the hanger at the generator's balance point.
  2. Fit the end tabs of the hanger through the bracket slots.
  3. Bolt the brackets to the hanger and tighten securely.
  4. Torque to 19.5 lbf·ft (26.5 N·m, 2.7 kgf·m).
Wheel Kit Installation installation

Tools: 12 mm wrench (2), pliers

  1. Install the two stands on the under frame using four 8×16 mm flange bolts.
  2. Install the two wheels on the axle shaft using the washers and split pins; bend the pins.
  3. Install the axle assembly using four 8×16 mm flange bolts and 8 mm flange nuts.
  4. Torque to 19.5 lbf·ft (26.5 N·m, 2.7 kgf·m).
Air Cleaner Element Cleaning maintenance

⚠ Do not twist the foam filter when squeezing.

⚠ Prevent dirt from entering the air duct that leads to the carburetor.

  1. Clean the foam air filter in warm soapy water, rinse, and allow to dry thoroughly, or clean in non-flammable solvent and dry.
  2. Dip the foam air filter in clean engine oil, then squeeze out all excess oil.
  3. Wipe dirt from the air cleaner housing and cover using a moist rag.
Air Cleaner Service maintenance

⚠ Never run the generator without the air filter.

⚠ Engine will smoke during initial startup if too much oil is left in the air filter.

  1. Unsnap the air cleaner cover clips, remove the cover, and remove the element.
  2. Wash the air filter in household detergent and warm water, or nonflammable/high flashpoint solvent; rinse thoroughly.
  3. Allow the air filter to dry thoroughly.
  4. Soak the air filter in clean engine oil and squeeze out the excess oil.
  5. Reinstall the air cleaner element and the cover.
Draining the Fuel Tank and Carburetor maintenance

⚠ Gasoline is highly flammable and explosive; keep heat, sparks, and flame away.

⚠ Handle fuel only outdoors.

Tools: funnel

  1. Turn the fuel valve lever to the OFF position.
  2. Place a suitable gasoline container below the carburetor.
  3. Loosen the carburetor drain screw and drain the gasoline.
  4. Tighten the carburetor drain screw securely.
  5. Place a container below the sediment cup and remove the sediment cup.
  6. Turn the fuel valve lever to ON and drain the fuel from the tank.
  7. Install the sediment cup and a new O-ring.
Engine Oil Change maintenance

⚠ Wash your hands with soap and water after handling used oil.

⚠ Dispose of used oil properly.

  1. Place a suitable container below the engine.
  2. Remove the oil filler cap/dipstick, 12×15 mm drain plug, and sealing washer.
  3. Allow the used oil to drain completely.
  4. Reinstall the drain plug and a new sealing washer; tighten securely.
  5. Fill to the upper limit mark with recommended oil.
  6. Reinstall the oil filler cap/dipstick securely.
Engine Oil Level Check maintenance
  1. Remove the oil filler cap/dipstick and wipe it clean.
  2. Insert and remove the dipstick without screwing it into the filler neck; check the oil level.
  3. If the oil level is low, fill to the upper limit mark with recommended oil.
  4. Reinstall the oil filler cap/dipstick securely.

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

Parts cataloged across the Honda GX340 family

198
Part #DescriptionCategory
0601800258AC VOLTMETERac_voltmeter
17210-ZE3-505Air filterair_filter
17211899000ELEMENT AIR CLEANERair_filter
52-53Air Cleaner Assemblyair_filter
573-012Air Cleaner Assemblyair_filter
0602313060ARRESTER, SPARKarrester_spark
HONDA18355ZB4630ARRESTER, SPARKarrester_spark
957251008000BOLT, FLANGE, 10X80bolt_flange_10x80
957010600800BOLT, FLANGE, 6X8bolt_flange_6x8
0040120000BOLT, FLANGE, 8X98bolt_flange_8x98
90014ZE2000BOLT, HEAD COVERbolt_head_cover
0040170000BOLT, STUD, 8X47bolt_stud_8x47
90047ZE2000BOLT, STUD, 8X47bolt_stud_8x47
90042ZE3700BOLT, STUD, 8X98bolt_stud_8x98
7905461004BRACKETbracket
7905469004BRACKETbracket
4341817004BRACKET, CIRCUIT BREAKERbracket_circuit_breaker
0601805327CIRCUIT BREAKERbreaker
0601851760CAPcap
0810106004CAP, FUEL TANKcap_fuel_tank
16100ZEZF00CARBURETOR ASSY.carburetor
28410ZE3W01ZBCASE COMP., RECOIL STARTERcase_comp_recoil_starter
0601804819CIRCUIT BREAKERcircuit_breaker
12216ZE2300CLIP, VALVE GUIDEclip_valve_guide
0805088304COLLARcollar
7901810203CONTROL BOXcontrol_box
7911811403CONTROL BOXcontrol_box
7901820103CONTROL PANELcontrol_panel
7911821413CONTROL PANELcontrol_panel
7915455003COVERcover
7915455103COVERcover
12310ZE2010COVER COMP., HEADcover_comp_head
0820610304DECAL : CAUTIONdecal_caution
S-1123DECAL : GROUNDdecal_ground
7900681202DECAL : MQ 6000decal_mq_6000
S-4499DECAL : MQ 6000decal_mq_6000
7900501222DECAL : MQ GA-6HZRdecal_mq_ga_6hzr
0605511087FUEL COCKfuel_cock
16950ZB4015FUEL COCK ASSY.fuel_cock
0810107103FUEL FILTERfuel_filter
17672-ZE2-W01Fuel strainerfuel_filter
A9924800004FILTER FUELfuel_filter
0601830737FULL POWER SWITCHfull_power_switch
0602320175GASKETgasket
11381-ZE3-801Gasket, sump covergasket
12251-ZE3-000Gasket, cylinder headgasket
12391-ZE2-020Gasket, rocker covergasket
16220-ZA0-702Gasket, air cleaner housinggasket
16221-ZF6-800Gasket, carbgasket
16223-ZE3-W00Gasket, carb insulatorgasket
18333-ZE3-800Gasket, muffler pipegasket
18381-ZE2-W10Gasket, mufflergasket
HONDA18333ZB4800GASKETgasket
12251ZE3W00GASKET, CYLINDER HEADgasket_cylinder_head
18333ZE3800GASKET, EX. PIPEgasket_ex_pipe
28469ZE2W01GRID REINFORCEMENTgrid_reinforcement
28461ZE2W01GRIP, STARTERgrip_starter
0601850102GROMMETgrommet
7901850004GROMMETgrommet
0601815109GROUND TERMINALground_terminal
12205ZE2315GUIDE, EX. VALVE (OVER SIZE)guide_ex_valve_over_size
12204ZE2325GUIDE, IN. VALVE (OVER SIZE)guide_in_valve_over_size
122AOZF6W00HEAD COMP., CYLNDERhead_comp_cylinder
0010108020HEX. HEAD BOLThex_head_bolt
0017105010HEX. HEAD BOLThex_head_bolt
0017106012HEX. HEAD BOLThex_head_bolt
0017106016HEX HEAD BOLThex_head_bolt
0017106020HEX. HEAD BOLThex_head_bolt
0017108020HEX. HEAD BOLThex_head_bolt
0017108025HEX. HEAD BOLThex_head_bolt
0017108030HEX. HEAD BOLThex_head_bolt
0017108040HEX. HEAD BOLThex_head_bolt
0602322061HEX. HEAD BOLThex_head_bolt
OB-13HEX. HEAD BOLThex_head_bolt
0207004000HEX. NUThex_nut
0207008000HEX. NUThex_nut
28445ZE2W01HOLDER, SPRINGholder_spring
95001-45300-40SFuel linehose
HONDA16950ZB4015HOSEhose
HONDA950001-4519040HOSEhose
0605513140HOSE BANDhose_band
HONDA95700-08020-00HOSE BANDhose_band
0601830727IDLE CONTROL SWITCHidle_control_switch
0027103020MACHINE SCREWmachine_screw
0027104010MACHINE SCREWmachine_screw
7912310003MUFFLERmuffler
7900501212NAME PLATEname_plate
9405008000NUT, FLANGE, 8MMnut_flange_8mm
15600735700DIPSTICKoil_filter
0601830738OPERATION SWITCHoperation_switch
04108-ZE2-000Rocker coverother_service
0800628504DECAL : GROUNDother_service
0820610404NOTE PAGEother_service
13010-ZE3-003Ring set (std)other_service
13101-ZE3-W00Piston (std)other_service
13200-ZE3-020Connecting rod (std)other_service
14711-ZE3-000Valve, intakeother_service
14721-ZE3-000Valve, exhaustother_service
1560-735-00Oil cap and indicatorother_service
15600-ZG4-003Oil capother_service
16100-ZE3-V01Carb assy.other_service
16610-ZE1-000Choke leverother_service
1665419004SHOCK MOUNTother_service
16955-ZE1-000Fuel tank jointother_service
1725419214RUBBER SUSPENSIONother_service
17510-ZE3-010Fuel tankother_service
17620-ZH7-023Fuel capother_service
18310-ZE2-W61Muffler assy.other_service
18320-ZE3-W01Muffler shieldother_service
18330-ZH9-N00Muffler pipeother_service
19610-ZE3-010ZABlower housingother_service
28462ZV7003ROPE, RECOILother_service
30009010Pilot screwother_service
3015419604SHOCK MOUNTother_service
34150-ZH7-003Diode assyother_service
34150ZH7003ALERT UNIT, OILother_service
36-37Cylinder Head Assemblyother_service
36100-ZE1-015Switch, on/offother_service
40-41Fan Cover Assemblyother_service
42-43Camshaft/Valves Assemblyother_service
44-45Crankcase Assemblyother_service
46-47Crankshaft, Piston Assemblyother_service
48-49Governor Assemblyother_service
50-51Air Cleaner Assemblyother_service
54-55Camshaft Assemblyother_service
56-57Carburetor Assemblyother_service
573-014Cylinder Barrel (Recoil) Assemblyother_service
573-028Fan Cover Assemblyother_service
573-049Crankcase Cover/Governor Assemblyother_service
573-052Idle Control Switchother_service
573-054Full Power Switchother_service
573-058Operation Switchother_service
573-062AC Voltmeterother_service
573-064Idle Control Switchother_service
573-068Full Power Switchother_service
573-072Operation Switchother_service
573-084AC Voltmeterother_service
58-59Control Assemblyother_service
60-61Crankcase Cover Assemblyother_service
62-63Crankshaft Assemblyother_service
64-65Cylinder Barrel Assemblyother_service
66-67Cylinder Head Assemblyother_service
68-69Fan Cover Assemblyother_service
70-71Flywheel Assemblyother_service
72-73Ignition Coil Assemblyother_service
74-75Piston Assemblyother_service
78-79Solenoid Assemblyother_service
7900636004DECAL : OPERATE AT 3600 RPM ONLYother_service
80-81Label Assemblyother_service
8700611804P/N 8700611804other_service
8700611904P/N 8700611904other_service
96100-62070-000Ball bearing, crankshaftother_service
A9924800014CAP FUEL TANKother_service
12391ZE2010PACKING, HEAD COVERpacking_head_cover
9430112200PIN, DOWEL, 12X20pin_dowel_12x20
18330ZE3700PIPE, EX.pipe_ex_
0041208000PLAIN WASHERplain_washer
9807955855PLUG, SPARK (W16EPRU ND)plug_spark_w16epru_nd
0602302001PROTECTOR, MUFFLERprotector_muffler
0602302002PROTECTOR, MUFFLERprotector_muffler
HONDA18320ZC2000PROTECTOR, MUFFLERprotector_muffler
HONDA18325ZB4000PROTECTOR, MUFFLERprotector_muffler
28421ZE3W01PULLEY, RECOIL STARTERpulley_recoil_starter
28422ZE2W01RATCHET, STARTERratchet_starter
95/27.5Rated Ampsrated_current_a
28400ZEZW01ZBRECOIL STARTERrecoil_start
28400ZE3W01ZBSTARTER ASSY, RECOILrecoil_start_assy
0601823204RECTIFIERrectifier
28444ZE2W01RETAINER, SPRINGretainer_spring
28462ZE3W01ROPE, RECOIL STARTERrope_recoil_starter
7901002403ROTOR ASS’Yrotor_assy
0805088004RUBBER CUSHIONrubber_cushion
0602302003SEALseal
91201-ZE3-004Oil seal PTOseal
HONDA18329ZB4000SEALseal
15510-ZE2-033Oil level switchsensor
15510ZE2W01OIL LEVEL SWITCHsensor
30500-ZE2-023Ignition coilsensor
7901316004SET BOLT, STATORset_bolt_stator
0601823853SLOW DOWN UNITslow_down_unit
31ZH9600Spark arrester screenspark_plug
9807955846SPARK PLUGspark_plug
28441ZE2W01SPRING, FRICTIONspring_fricition
28443ZE2W01SPRING, RATCHETspring_ratchet
28442ZE2W01SPRING, STARTER RETURNspring_starter_return
28400-ZE3-W01ZAStarter assy., NEW STYLEstarter
28422-ZE2-W01Starter pawlstarter
28434-ZE8-811Starter pawl retainerstarter
28442-ZE2-W01Starter springstarter
28443-ZE2-W01Starter pawl springstarter
28451-ZE3-A02Starter cupstarter
38-39Recoil Starter Assemblystarter
76-77Recoil Starter Assemblystarter
90003-ZG0-003Starter center screwstarter
TNR15G431KSURGE ABSORBERsurge_absorber
0602322060TAPPING SCREWtapping_screw
HONDA90183-671-003TAPPING SCREWtapping_screw
90441ZE2010WASHER COMP., HEAD COVERwasher_comp_head_cover

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Aftermarket parts that fit this engine

3
12209-ZE8-003 FridayParts $15.00 19511-ZE3-000 FridayParts $26.56 16551-ZE3-000 FridayParts $16.05

Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.

Common questions

What is the oil capacity of the Honda GX340 K1?

The Honda GX340 K1 engine has an oil capacity of 1.1 liters.

What is the displacement of the Honda GX340 K1?

The Honda GX340 K1 has a displacement of 0.625 liters with 1 cylinders.

Which generators use the Honda GX340 K1 engine?

The Honda GX340 K1 powers 2 generator set(s), including Honda EB5000, MQ Power GA-6H.

How often should you change the oil in the Honda GX340 K1?

The Honda GX340 K1 oil change interval is every 200 hours.

What is a common problem with the Honda GX340 K1 engine?

A commonly reported issue on generators using the Honda GX340 K1 is: Rectifier failure. Fix: Replace the rectifier.