HomeGeneracGenerac QT 40kW

Generac QT 40kW Generator Set

The Generac QT 40kW is a 40 kW standby generator set powered by a Mitsubishi 3.9L engine.

40 kW
Standby
3.9 L
Displacement
1
Document types

How to read your Generac serial & model number →

Specifications

Standby power40 kW

Engine

Mitsubishi 3.9L
Displacement3.9 L

Maintenance & consumables

for the Mitsubishi 3.9L
ItemSpecCapacityPart #Interval
Air filter0A4637500 hr Amazon eBay $49.95 PartsGeek
Oil filter0E7415250 hr Amazon eBay $47.95 PartsGeek
Belt3/8 to 5/8 inch deflection find
Coolant
Oil4.0 liters150 hr

Common questions

What is the power rating of the Generac QT 40kW?

The Generac QT 40kW is rated 40 kW standby.

What engine does the Generac QT 40kW use?

The Generac QT 40kW is powered by the Mitsubishi 3.9L engine.

Troubleshooting

7

Fault codes

CodeMeaning
Safety 001DANGER

Symptoms & remedies

SymptomCauseRemedy
Engine won’t crank.1. 15 amp fuse blown. 2. Loose or corroded or defective battery cables. 3. Defective starter contactor. 4. Defective starter motor. 5. Dead or Defective Battery. 6. 5 amp fuse blown.1. Replace fuse. 2. Tighten, clean or replace battery cables as necessary. 3. Replace contactor.* 4. Replace starter motor.* 5. Remove, change or replace battery. 6. Replace fuse.*
Engine cranks but won't start1. Out of fuel. 2. Fuel solenoid (FS) is defective 3. Open Wire #14A from Engine Control circuit board. 4. Spark plugs defective. 5. Door on tank not closed.1. Replenish fuel. 2. Replace solenoid.* 3. Reconnect wire. 4. Clean, regap or replace plugs. 5. Close door on tank.
Engine starts hard, runs rough.1. Flame arrestor (air cleaner) plugged or damaged. 2. Plugged fuel line. 3. Defective spark plugs. 4. Fuel pressure incorrect.1. Clean or replace as needed. 2. Unclog fuel line. 3. Clean, regap or replace plugs. 4. Confirm fuel pressure to regulator is as recommended in SPECIFICATIONS.
Engine starts then shuts down.AUTO/OFF/MANUAL Switch at OFF, engine continues to run*Contact the nearest Authorized Dealer for assistance.
No AC output from generator.Defective Control Module circuit board*Contact the nearest Authorized Dealer for assistance.
Defective AUTO/OFF/MANUAL switch.1. Open/disconnected wire #15A between AUTO/OFF/MANUAL switch and Control Module circuit board.Replace switch.* Reconnect/close wire.

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

Parts

250
Part #DescriptionQtySystem
035606SENSOR HI COOLANT SHUTDOWN1Sensor PartsGeek
035685CLAMP HOSE #28 1.32-2.254Hose PartsGeek
040105HOSE COOL 2IN ID 20R4 (2” LG)1Hose PartsGeek
042561CLAMP HOSE #36 1.88-2.752Hose PartsGeek
048031CCLAMP HOSE BAND 1/41Hose PartsGeek
048031JHOSE CLAMP BAND 5/8"Hose PartsGeek
057822CLAMP HOSE #8 .53-1.001Hose PartsGeek
057823CLAMP HOSE #10 .56-1.062Hose PartsGeek
057824CLAMP HOSE #16 .87-1.50 (3600 RPM)1Hose PartsGeek
058208BATT 12VDC 24F 625Battery Amazon eBay $50.00 PartsGeek
059057HOSE 3/4 ID SAE-30R2 (17” LG)1Hose PartsGeek
059193CHOSE 5/8 ID X 31.0" LG1Hose PartsGeek
064945GASKET CARB ADAPTOR1Gasket PartsGeek
069860EHOSE DRAIN ASSY 28"1Hose PartsGeek
0A4637Air CleanerAir filter Amazon eBay $49.95 PartsGeek
0A8584OIL FILTER1Oil filter PartsGeek FridayParts $31.60
0C7649CLAMP HOSE .38-.871Hose PartsGeek
0D3488HSERPENTINE BELT (60.5")1Belt Amazon eBay $49.99 PartsGeek
0E0561ASSY WATER LEVEL SENSOR C/E PL1Sensor PartsGeek
0E0992BPLUG EXPANSION 21/32" O.D. (WATER PUMP)Pump PartsGeek
0E5968GASKET EXTRUDED TRIM (328” LG)1Gasket PartsGeek
0E6586GASKET BOSCH 32 & 401Gasket PartsGeek
0E6729STARTER 12V1Starter PartsGeek
0E7121O-RING 47.625 ID X 2.38 WIDTH1Seal PartsGeek
0E7415Oil Filter1Oil filter Amazon eBay $47.95 PartsGeek
0E7702HOLD DOWN AIR CLEANER1Air filter PartsGeek
0E7841GASKET THERMOSTAT ADAPTOR2Gasket PartsGeek
0E9868AD.C. ALTERNATOR W/OUT PULLEY1Alternator PartsGeek
0F3216PULLEY 80 OD DC ALTERNATOR (1800 RPM)1Alternator PartsGeek
0F3216CPULLEY 132 OD DC ALTERNATOR (3600 RPM)1Alternator PartsGeek
0F3446BRKT R/H SIDE D.C. ALTERNATOR1Alternator PartsGeek
0F3447BRKT L/H SIDE D.C. ALTERNATOR1Alternator PartsGeek
0F4413HOSE UPPER RAD CPL C2 3.9L1Hose PartsGeek
0F4414HOSE LOWER RAD CPL C2 3.9L1Hose PartsGeek
0F5418ELEMENT AIR FILTER1Air filter Amazon eBay $18.99 PartsGeek
0F6145SEAL WEATHER .45"DIASeal PartsGeek
0F6305SEAL COVER 3.18 X 12.7 X 3822Seal PartsGeek
0F6305ASEAL COVER 3.18 X 12.7 X 2831Seal PartsGeek
0F6322BOTTOM PLATE, AIR CLEANER 3.9L1Air filter PartsGeek
0F6323PLATE, AIR CLEANER TOP 3.9L1Air filter PartsGeek
0F6480BRKT L/H SIDE DC ALTERNATOR1Alternator PartsGeek
RC12LC4Spark PlugSpark plug Amazon eBay $26.61 PartsGeek
023454KEY WOODRUFF #E1Service part / kit PartsGeek
023484NBUSHING SNAP SB-2.5-311Service part / kit PartsGeek
025433LUG SLDLSS #6-14 X 13/64 CU1Service part / kit PartsGeek
026812ELBOW 90D 3/4 NPT2Service part / kit PartsGeek
026915NIPPLE CLOSE 3/4 X 1.3752Service part / kit PartsGeek
026925PLUG STD PIPE 3/8 STEEL SQ HD1Service part / kit PartsGeek
029289TAPE ELEC 1/2 FOAM (AS REQ’D)1Service part / kit PartsGeek
029673DIO BRIDGE 25A 600V1Service part / kit PartsGeek
031919PLUG STD PIPE 3/8 COUNTERSUNKService part / kit PartsGeek
036797BOLT U 5/16-18 X 2.254Service part / kit PartsGeek
037561NUT WING 1/4-20 NYLK1Service part / kit PartsGeek
038804YCABLE BATT RED #1 X 35.001Service part / kit PartsGeek
038805HCABLE BATT BLK #1 X 23.001Service part / kit PartsGeek
040532CB 0100A 3P 240V S BQ3 LLService part / kit PartsGeek
043790BARBED EL 90 3/8 NPT X 3/81Service part / kit PartsGeek
044118BARBED STR 1/2 NPT X 5/81Service part / kit PartsGeek
04576100AQSTUD M14-2.0 X 615 G5 ZINC4Service part / kit PartsGeek
04576100BUSTUD M14-2.0 570 G5 ZINC (30KW)4Service part / kit PartsGeek
046627Radiator CapService part / kit PartsGeek
047248BALL BEARING-45 MM1Service part / kit PartsGeek
048467CIRCT BRK 7 X 1 ETA 46-500-P1Service part / kit PartsGeek
050279NG fuel inlet decal1Service part / kit PartsGeek
050280LPG fuel inlet decal1Service part / kit PartsGeek
050331BATT POST COVER BLK1Service part / kit PartsGeek
050331ABATT POST COVER RED +1Service part / kit PartsGeek
050873APLUG PIPE 1/4 CSK W/ VIBRA SLService part / kit PartsGeek
052250TAPE FOAM 1 X 1 (22.5” LG)2Service part / kit PartsGeek FridayParts $16.89
052251DAMPENER VIBRATION 40 BLUE4Service part / kit PartsGeek
052252DAMPENER VIBRATION4Service part / kit PartsGeek
052257SPACER .49 X .62 X 1.87 PWDR/ZNC4Service part / kit PartsGeek
052677WASHER NYLON .50 X .87 X .061Service part / kit PartsGeek
052860NUT FLANGED HEX M12-1.754Service part / kit PartsGeek
0536210410ASSY WIRE 14.00"1Service part / kit PartsGeek
054455ADP OIL DRN 1/2-201Service part / kit PartsGeek
055414LUG SLDLSS #2-#8 X 17/64 CU1Service part / kit PartsGeek
055596BARBED STR 3/8 NPT X 3/81Service part / kit PartsGeek
055911BLOCK TERM 20A 12 X 6 X 1100V1Service part / kit PartsGeek
055934DCLAMP VINYL 1.06 X .406 Z1Service part / kit PartsGeek
056739RELAY SOLENOID 12VDC PNL MNT1Service part / kit PartsGeek
057073JUNCTION BLOCK 3/8-162Service part / kit PartsGeek
057701BLOCK TERM 20A 8 X 6 X 1100VService part / kit PartsGeek
057795ABARBED EL 90 3/4 PLASTIC1Service part / kit PartsGeek
057796GROMMET1Service part / kit PartsGeek
061012PLUG STD PIPE 1/8 SOCKET HEADService part / kit PartsGeek
065852SPRING CLIP HOLDER .37-.621Service part / kit PartsGeek
067210ADECAL GROUND LUG1Service part / kit PartsGeek
067377Start-up Inspection for Standby Power SystemsService part / kit PartsGeek
067680ASSY VOLTAGE REGULATOR 60HZ1Service part / kit PartsGeek
069811CAP HEX 1/4 NPT BRASSService part / kit PartsGeek
070892SLIP RING MACHINED1Service part / kit PartsGeek
075580FLANGE FUEL INLET1Service part / kit PartsGeek
075763BOOT BATTERY CABLE1Service part / kit PartsGeek
076749TANK COOLANT RECOVERY1Service part / kit PartsGeek
077043FCONDUIT FLEX 1-1/4" (30” LG)1Service part / kit PartsGeek
077043JCONDUIT FLEX 2.0" ID (36” LG)1Service part / kit PartsGeek
077992NUT HEX LOCK M6-1.0 SS NY INS21Service part / kit PartsGeek
080712BRKT COOLANT RECOVERY TANK1Service part / kit PartsGeek
080762BOLT U 3/8-16 X 2.621Service part / kit PartsGeek
081008GROMMET 1.25 X .25 X .751Service part / kit PartsGeek
082573SWITCH RKR DPST 125V SPD1Service part / kit PartsGeek
087233RIVET POP .1875 X .450 SS2Service part / kit PartsGeek
089514FTG CMPR 3/8TUBE X 3/8 NPT W/FERL1Service part / kit PartsGeek
089685GROMMET .75 X .12 X .501Service part / kit PartsGeek
089961FOAM STRIP 3/4" WIDE X 3/16" THK (46” LG)1Service part / kit PartsGeek
090283CAP RADIATOR 13 PSI1Service part / kit PartsGeek
0912970094ASSY WIRE 14 AWG 34.8" GRN/YEL2Service part / kit PartsGeek
0A2077CB 0125A 2P 240V S BQ2 LL1Service part / kit PartsGeek
0A5062JSPACER 9.5H 3.2 ID4Service part / kit PartsGeek
0A7822LUG SLDLSS 600/250-1/0 X 1/4-283Service part / kit PartsGeek
0A9457DECAL NEUTRAL1Service part / kit PartsGeek
0C2634AASSEMBLY COVER ACCESS1Service part / kit PartsGeek
0C3397FASTENER RATCHET4Service part / kit PartsGeek
0C9708INSTR HYPOT TEST1Service part / kit PartsGeek
0D1509DECAL INLET PRESSURE1Service part / kit PartsGeek
0D2244MASSY MAGPICKUP (3/8-24 MALE)1Service part / kit PartsGeek FridayParts $18.08
0D4698BLOCK TERM 20A 6 X 3 X 1100VService part / kit PartsGeek
0D5466BUS BAR NEUTRAL BLOCK 3902Service part / kit PartsGeek
0D5552CB 0050A 3P 480V S ED4 LL1Service part / kit PartsGeek
0D5553CB 0060A 3P 480V S ED4 LLService part / kit PartsGeek
0D5554CB 0070A 3P 480V S ED4 LLService part / kit PartsGeek
0D5556CB 0090A 3P 480V S ED4 LLService part / kit PartsGeek
0D5572CB 0150A 3P 600V S FD6 LL1Service part / kit PartsGeek
0D5573CB 0175A 3P 600V S FD6 LLService part / kit PartsGeek
0D5574CB 0200A 3P 600V S FD6 LLService part / kit PartsGeek
0D5575CB 0225A 3P 600V S FD6 LLService part / kit PartsGeek
0D5576CB 0250A 3P 600V S FD6 LLService part / kit PartsGeek
0D5577CB 0300A 3P 600V S JD6 LL1Service part / kit PartsGeek
0D9693CB 0125A 3P 480V S ED4 LLService part / kit PartsGeek
0D9832SCREW HHC M12-1.75 X 75 SS4Service part / kit PartsGeek
0E0992APLUG EXPANSION 14.1 O.D. (INJCTOR HOLE)Service part / kit PartsGeek
0E2507PROBE COOLANT LEVEL 3/8 NPTF1Service part / kit PartsGeek
0E3161ASSY PCB BOSCH GOV DRIVER1Service part / kit PartsGeek
0E3664BASE, QN CIRCUIT BREAKER1Service part / kit PartsGeek
0E4394ACTUATOR BOSCH 40, GOVERNOR1Service part / kit PartsGeek
0E4494SWITCH RKR DPDT ON-OFF-ON1Service part / kit PartsGeek
0E5048AFLEXPLATE HSB 3.9L CHRYSLER (1800RPM)1Service part / kit PartsGeek
0E5706REAR BEARING CARRIER 390/DRCT1Service part / kit PartsGeek
0E6002MTG TRACK BQ SIEMENS CB 3PService part / kit PartsGeek
0E6076REVCOR FAN 12.63 X 2 W/PRESSDISK1Service part / kit PartsGeek
0E6376BVENTURI 28 ID THROTTLE W/CHOKE1Service part / kit PartsGeek
0E6382BVENTURI HOLDER W/40MM ACTUATOR1Service part / kit PartsGeek
0E6406HOLDER VENTURI1Service part / kit PartsGeek
0E6703COVER FLYWHEEL ACCESS1Service part / kit PartsGeek
0E6875ARELAY 12VDC C FORM W/DIODE2Service part / kit PartsGeek
0E7254MACH THERM ADAPTOR 3.9L CHRY1Service part / kit PartsGeek
0E7283CB 0150A 2P 240V S QN2 LLService part / kit PartsGeek
0E7284CB 0175A 2P S QN2 LL 240VService part / kit PartsGeek
0E7403CFUSE ATO TYPE 15 AMP (BLUE)1Service part / kit PartsGeek
0E7839MACHINING, CARBURETOR ADAPTOR1Service part / kit PartsGeek
0E7854CLUTCH COOLING FAN1Service part / kit PartsGeek
0E7855TENSIONER W/BRACKET1Service part / kit PartsGeek
0E7890BRKT CB MTG BACK1Service part / kit PartsGeek
0E7950TUBE DIPSTICK 3.9L CHRYSLER1Service part / kit PartsGeek
0E7951DIPSTICK OIL LEVEL 3.9L CHRYSLER1Service part / kit PartsGeek
0E7952PULLEY CRANKSHAFT 3.9L CRYSLR (1800 RPM)1Service part / kit PartsGeek
0E7953COIL IGNITION 3.9L CHRYSLER1Service part / kit PartsGeek
0E7954CABLE IGN COIL 3.9L CHRYSLER1Service part / kit PartsGeek
0E7956BRACKET IGNITION COIL1Service part / kit PartsGeek
0E7994CB 0225A 240V 2P S QJ22Service part / kit PartsGeek
0E8286STREET EL 45 DEG 1/2" NPT BRASS1Service part / kit PartsGeek
0E8336MAKE 3.9L CHRYSLER ENGINE (1800 RPM)Service part / kit PartsGeek
0E8445BRACKET DIPSTICK TUBE1Service part / kit PartsGeek
0E8731PLATE FLEX DISK SPACER (1800 RPM)1Service part / kit PartsGeek
0E8816EXHAUST FLANGE 2" PIPE1Service part / kit PartsGeek
0E9295ASSY THROTTLE 28MM1Service part / kit PartsGeek
0E9975CAP VINYL 1/4" ID X 1" DP BLK1Service part / kit PartsGeek
0F0199INSULATOR CB FD FRAME 30MIL1Service part / kit PartsGeek
0F0492INSULATOR CB S (ED-3P)1Service part / kit PartsGeek
0F0738MUFFLER 7" X 9"-(2) 2" IN/2.5" OUT1Service part / kit PartsGeek
0F1262HOLDER FUSE WICKMANN 178.61504Service part / kit PartsGeek
0F1263ADPTR RH SIDE WICKMAN 178.61911Service part / kit PartsGeek
0F1264ADPTR LH SIDE WICKMAN 178.61921Service part / kit PartsGeek
0F1444HEAT SHIELD R/H SIDE1Service part / kit PartsGeek
0F1444AHEAT SHEILD L/H SIDE1Service part / kit PartsGeek
0F1725CASSY PCB 2AMP 12V UL BATT CHGR1Service part / kit PartsGeek
0F1733DECAL CUSTOMER CONNECT INSIDE1Service part / kit PartsGeek
0F1823AENCL HSB CONTROL PANEL1Service part / kit PartsGeek
0F1958PLATE,HARNESS CLAMP1Service part / kit PartsGeek
0F2230SUPPORT ENGINE 3.9L LH & RH SD2Service part / kit PartsGeek
0F2353INSULATOR CIRCUIT BR. JD/LD2Service part / kit PartsGeek
0F2606HINGE CONTINUOUS H-PANEL1Service part / kit PartsGeek
0F2608RADIATOR 598 X 568 X 49 CPL RH1Service part / kit PartsGeek
0F2627ACOVER CONTROL PANEL SIDE1Service part / kit PartsGeek
0F2694APULLEY CRANKSHAFT (3600 RPM)1Service part / kit PartsGeek
0F2785SPLITTER LOWER C41Service part / kit PartsGeek
0F2786SLITTER C42Service part / kit PartsGeek
0F2808BPIPE EXHAUST MUFFLER OUT1Service part / kit PartsGeek
0F2820FAN 22" DIA 10 BLADE1Service part / kit PartsGeek
0F2830MUFFLER BRACKET STIFFENER1Service part / kit PartsGeek
0F2962MUFFLER STRAP1Service part / kit PartsGeek
0F2982ENG ADAPTER MACH 3.9L HSB NSPS1Service part / kit PartsGeek
0F3072INSULATION RETAINMENT HANGER10Service part / kit PartsGeek
0F3078COVER CONTROL PANEL1Service part / kit PartsGeek
0F3127PIPE L/H SIDE 3.9L CPL1Service part / kit PartsGeek
0F3133PIPE R/H SIDE 3.9L CPL1Service part / kit PartsGeek
0F3137PAN CB CONN BOX1Service part / kit PartsGeek
0F3138COVER CB CONN BOX1Service part / kit PartsGeek
0F3188STAND RH CONTROL1Service part / kit PartsGeek
0F3189STAND LH CONTROL1Service part / kit PartsGeek
0F3192SUPPORT ANGLE PCB1Service part / kit PartsGeek
0F3203WELDMENT RAD SUPPORT 3.9L C21Service part / kit PartsGeek
0F3215DECAL CONTROL HSB1Service part / kit PartsGeek
0F3217SPACER DC ALTERNATOR PULLEY1Service part / kit PartsGeek
0F3270MTG BASE 3.9L 40KW C21Service part / kit PartsGeek
0F3312DUCT INNER DISCHARGE TOP C21Service part / kit PartsGeek
0F3313DUCT INNER DISCHARGE C21Service part / kit PartsGeek
0F3328COVER ED CB SHORT STND1Service part / kit PartsGeek
0F3329COVER JD/LD CB SHRT STAND1Service part / kit PartsGeek
0F3364SPLITTER STINGER C21Service part / kit PartsGeek
0F3408TRAY BATTERY1Service part / kit PartsGeek
0F3411STRAP BATTERY RETAINMENT1Service part / kit PartsGeek
0F3438RTR 390 30AD1 CPL1Service part / kit PartsGeek
0F3439STR 390 30AD1 CPL1Service part / kit PartsGeek
0F3440RTR 390 40AD2 CPL HI-EF1Service part / kit PartsGeek
0F3441STR 390 40AD2 CPL1Service part / kit PartsGeek
0F3641HARN ENG 3.9L 3600 RPM FLEX PNL (NOT SHOWN)(3600 RPM)1Service part / kit PartsGeek
0F3760EINSULATION SPLITTER2Service part / kit PartsGeek
0F3760KINSULATION SPLITTER2Service part / kit PartsGeek
0F3760LINSULATION LOWER SPLITTER1Service part / kit PartsGeek
0F3794EXHAUST BLANKET 549MM LONG (R/H)1Service part / kit PartsGeek
0F3794AEXHAUST BLANKET 448MM LONG (L/H)1Service part / kit PartsGeek
0F3795ENGINE INSERTED VALVE 3.9L (3600 RPM)Service part / kit PartsGeek
0F3824DECAL UTIL SENSE/CUST CONN1Service part / kit PartsGeek
0F3869SWITCH PRESSURE GAS 5" RISE (INCLUDED WITH I/N 3)1Service part / kit PartsGeek
0F3890RETAINER INSULATION (450)3Service part / kit PartsGeek
0F3890ARETAINER INSULATION (740)3Service part / kit PartsGeek
0F3890BRETAINER INSULATION (820)8Service part / kit PartsGeek
0F3890CRETAINER INSULATION (220)2Service part / kit PartsGeek
0F3903AFLEX PLATE 2 POLE 3.9L CHRY (3600RPM)1Service part / kit PartsGeek
0F4051INSULATION DOOR C22Service part / kit PartsGeek
0F4051AINSULATION ROOF TOP1Service part / kit PartsGeek
0F4051BINSULATION DUCT SIDES2Service part / kit PartsGeek
0F4051CINSULATION DUCT2Service part / kit PartsGeek
0F4051DINSULATION INNER DUCT3Service part / kit PartsGeek
0F4073CINSUL DUCT SIDE OR INNER DUCT1Service part / kit PartsGeek
0F4110BYPASS ORIFICE 3.9L CHRYSLER (3600 RPM)1Service part / kit PartsGeek
0F4143CB 0040A 3P 480V 225AF (3P)Service part / kit PartsGeek
0F4148CB 0125A 3P 480V G 225AFService part / kit PartsGeek
0F4149CB 0150A 3P 480V G 225AFService part / kit PartsGeek
0F4151CB 0200A 3P 480V G 225AFService part / kit PartsGeek
0F4185COVER CB C2-C4 (225AF)1Service part / kit PartsGeek
0F4186COVER CB DISH 225AF (3P)1Service part / kit PartsGeek
0F4186AGS0RCOVER CB DISH 225AF (2P)Service part / kit PartsGeek
0F4187COVER CB C2-C4 400AF1Service part / kit PartsGeek
0F4245EASSY PCB CPL CTRLR 1800 RPM1Service part / kit PartsGeek
0F4272HARN ENG 3.9L 1800 RPM FLEX PNL (NOT SHOWN)(1800 RPM)1Service part / kit PartsGeek
0F4416HARN 1800RPM R-100 CONTROL PNL (NOT SHOWN)1Service part / kit PartsGeek
0F4464DECAL CUST CONN 120V UTILITY1Service part / kit PartsGeek

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Fuel consumption

RatingLoadL/hgal/h
25%
50%
75%
100%

Available documents

Owner's manual — 0F3459 (Generac)