Specifications
Ratings spec sheet not in our library yet — see the documents below.
Filters & service parts
model family| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | C8127 | 150 hr | Amazon eBay $17.95 PartsGeek | ||
| Fuel filter | 0D6313 | Amazon eBay $9.26 PartsGeek | |||
| Oil filter | 070185B | 100 hr | Amazon eBay $12.95 PartsGeek | ||
| Belt | 924-0365 | 1000 hr | eBay PartsGeek | ||
| Coolant | 924-0370 | 1000 hr | eBay PartsGeek | ||
| Oil | 4.31 | — | 400 hr |
Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.
Common questions
What oil filter does the Generac GT-990 use?
The Generac GT-990 uses oil filter part number 070185B.
What fuel filter does the Generac GT-990 use?
The Generac GT-990 uses fuel filter part number 0D6313.
What air filter does the Generac GT-990 use?
The Generac GT-990 uses air filter part number C8127.
Troubleshooting
4Symptoms & remedies
| Symptom | Remedy |
|---|---|
| Generator Produces Zero Voltage or Residual Voltage | TEST 4 - PERFORM FIXED EXCITATION / ROTOR AMP DRAW PERFORM STATOR INSULATION RESISTANCE TEST - SECTION 1.4 PERFORM ROTOR INSULATION RESISTANCE TEST - SECTION 1.4 TEST 7 - TEST STATOR TEST 5 - WIRE CONTINUITY TEST 6 - FIELD BOOST TEST 8 - CHECK ROTOR CIRCUIT REPAIR OR REPLACE FUSES |
| Generator Produces Low Voltage at No-Load | TEST 11 - CHECK AC OUTPUT FREQUENCY TEST 12 - ADJUST ENGINE GOVERNOR TEST 12A - CHECK STEPPER MOTOR CONTROL TEST 2 - CHECK AC OUTPUT VOLTAGE TEST 13- ADJUST VOLTAGE REGULATOR |
| Generator Produces High Voltage at No-Load | REPLACE DEFECTIVE VOLTAGE REGULATOR |
| Voltage and Frequency Drop Excessively When Loads are Applied | TEST 14 - CHECK VOLTAGE AND FREQUENCY UNDER LOAD TEST 79 - CHECK IDLE CONTROL TRANSFORMER TEST 80 - CHECK LC1 & LC2 WIRING TEST 81 - CHECK IDLE CONTROL TRANSFORMER PRIMARY WIRING TEST 15 - CHECK FOR OVERLOAD CONDITION TEST 12 - CHECK AND ADJUST ENGINE GOVERNOR |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Parts
120model family| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 030340 | Hose, Fuel, 4.5" LG. | 1 | Hose | PartsGeek |
| 048031C | CLAMP HOSE BAND 1/4 | 2 | Hose | PartsGeek |
| 070185 | Oil Filter | 1 | Oil filter | Amazon eBay $19.97 PartsGeek |
| 070185F | Engine oil filter | 1 | Oil filter | Amazon eBay PartsGeek |
| 072347 | SPARK PLUG | 2 | Spark plug | Amazon eBay $2.50 PartsGeek |
| 078672 | SEAL, VALVE STEM D7 | 2 | Seal | PartsGeek |
| 087769 | FUEL FILTER | 1 | Fuel filter | Amazon eBay $49.99 PartsGeek |
| 0C2977 | GASKET, CRANK CASE | 1 | Gasket | PartsGeek |
| 0C2978 | GASKET, HEAD | 2 | Gasket | PartsGeek |
| 0C2979 | GASKET, VALVE COVER | 2 | Gasket | PartsGeek |
| 0C3005 | GASKET, BREATHER COVER | 1 | Gasket | PartsGeek |
| 0C3008 | SEAL, 38 I.D. CRANKSHAFT | 1 | Seal | PartsGeek |
| 0C5943 | SEAL, OIL PASSAGE | 1 | Seal | PartsGeek |
| 0C8127 | Air Filter | 1 | Air filter | Amazon eBay $28.00 PartsGeek |
| 0C9093 | HOSE, BREATHER | 1 | Hose | PartsGeek |
| 0CL3007 | SEAL, 42 I.D. CRANKSHAFT | 1 | Seal | PartsGeek |
| 0D3262 | ELEMENT, AIR CLEANER | 1 | Air filter | Amazon eBay PartsGeek |
| 0D4010 | KIT GASKET | 1 | Gasket | PartsGeek |
| 0D4024 | GASKET, CARB TO SPACER | 1 | Gasket | PartsGeek |
| 0D4123 | ASSEMBLY, OIL PUMP | 1 | Pump | PartsGeek |
| 0D4511 | PRECLEANER, AIR | 1 | Air filter | Amazon eBay $39.90 PartsGeek |
| 0D5282 | GASKET, MANIFOLD TO CARBURETOR | 1 | Gasket | PartsGeek |
| 0D6327 | GASKET, SPITBACK | 1 | Gasket | PartsGeek |
| 0D9000 | GASKET, HEAD (GT-760) | 2 | Gasket | PartsGeek |
| 0D9723 | Engine Air Filter | 1 | Air filter | Amazon eBay $17.45 PartsGeek |
| 0E9581 | Air Filter | 1 | Air filter | Amazon eBay $21.99 PartsGeek |
| 0G3332 | Air filter element | 1 | Air filter | Amazon eBay $15.99 PartsGeek |
| 0G5894 | Air Filter | 1 | Air filter | Amazon eBay $19.99 PartsGeek |
| 100-025 | Air Filter | 1 | Air filter | PartsGeek |
| 100-030 | Oil Filter | 1 | Oil filter | PartsGeek |
| 924-0365 | Belt, Generac OE | 1 | Belt | eBay PartsGeek |
| 924-0368 | Oil Filter, Generac OE | 1 | Oil filter | eBay PartsGeek |
| 924-0369 | Air Filter, Generac OE | 1 | Air filter | eBay PartsGeek |
| 924-0370 | Coolant, Generac OE | 1 | Coolant filter | eBay PartsGeek |
| 924-0371 | Fuel Filter, Generac OE | 1 | Fuel filter | eBay PartsGeek |
| 924-0380 | Battery, 12V, 75Ah | 1 | Battery | eBay PartsGeek |
| RC12YC | Spark Plug | 1 | Spark plug | Amazon eBay $12.98 PartsGeek |
| RC14YC | Spark plug (V-twin GT-990, one per cylinder) | 2 | Spark plug | Amazon eBay $6.77 PartsGeek |
| 021533 | SET, PISTON RING 90MM | 2 | Service part / kit | PartsGeek |
| 022097 | WASHER LOCK M6-1/4 | 4 | Service part / kit | PartsGeek |
| 022473 | WASHER FLAT 1/4-M6 ZINC | 1 | Service part / kit | PartsGeek |
| 031879 | WASHER FLAT #4 | 1 | Service part / kit | PartsGeek |
| 043790A | BARBED EL 90 3/8NPT X 3/8 | 1 | Service part / kit | PartsGeek |
| 049721 | SCREW HHC M6-1.0 X 35 G8.8 BLK | 4 | Service part / kit | PartsGeek |
| 052857 | NUT LOCK FLANGE M6-1.0 | 4 | Service part / kit | PartsGeek |
| 0536210209 | ASSEMBLY, WIRE | 1 | Service part / kit | PartsGeek |
| 066849B | SCREW HHTT M5-0.8 X 8mm | 1 | Service part / kit | PartsGeek |
| 071980 | PIN PISTON D20 | 2 | Service part / kit | PartsGeek |
| 071983 | RETAINER, PISTON PIN 20 | 4 | Service part / kit | PartsGeek |
| 072628 | NUT LOCK HEX M3-0.5 | 2 | Service part / kit | PartsGeek |
| 072694 | STUD, D20 PIVOT BALL | 4 | Service part / kit | PartsGeek |
| 074908 | SCREW HHTT M5-0.8 X 10 BP | 1 | Service part / kit | PartsGeek |
| 078699E | SLEEVE, SEAMED DOWEL 10 DIA. | 2 | Service part / kit | PartsGeek |
| 083897 | TAPPET, SOLID | 4 | Service part / kit | PartsGeek |
| 086061G | SLEEVING 1/2 | 1 | Service part / kit | PartsGeek |
| 086515 | KEEPER, VALVE SPRING | 8 | Service part / kit | PartsGeek |
| 086516 | VALVE, EXHAUST | 2 | Service part / kit | PartsGeek |
| 087680 | NUT WING M6-1.0 | 1 | Service part / kit | PartsGeek |
| 090388 | SCREW, TAPTITE M6-1.0 X 12 BP | 3 | Service part / kit | PartsGeek |
| 093064 | ASSEMBLY, OIL FILL CAP | 1 | Service part / kit | PartsGeek |
| 093873 | WASHER, LOCK RIB M6 | 2 | Service part / kit | PartsGeek |
| 0C2229 | VALVE, INTAKE | 2 | Service part / kit | PartsGeek |
| 0C2967 | PISTON, LC | 2 | Service part / kit | PartsGeek |
| 0C2969 | ASSEMBLY, CONNECTING ROD (GT-990) | 2 | Service part / kit | PartsGeek |
| 0C2976 | SCREW HHFC M8-1.25 X 65 | 12 | Service part / kit | PartsGeek |
| 0C2981 | ROCKER, COVER | 1 | Service part / kit | PartsGeek |
| 0C3003 | SEPARATOR, OIL BREATHER | 3 | Service part / kit | PartsGeek |
| 0C3006 | SCREW, HHFC M10-1.5 X 55 | 11 | Service part / kit | PartsGeek |
| 0C3009 | SPRING, OIL RELIEF | 2 | Service part / kit | PartsGeek |
| 0C3010 | BALL, 1/2D OIL RELIEF | 2 | Service part / kit | PartsGeek |
| 0C3011 | COVER, OIL RELIEF | 2 | Service part / kit | PartsGeek |
| 0C5313 | SCREEN, OIL PICKUP | 1 | Service part / kit | PartsGeek |
| 0C5315 | GEROTOR, OUTER | 1 | Service part / kit | PartsGeek |
| 0C5371 | WASHER, VALVE SPRING | 4 | Service part / kit | PartsGeek |
| 0C5372 | ASSEMBLY, BREATHER | 1 | Service part / kit | PartsGeek |
| 0C5729 | ASSEMBLY, CRANKCASE HOUSING WITH SLEEVE | 1 | Service part / kit | PartsGeek |
| 0C5731 | ASSEMBLY, HOUSING COVER WITH SLEEVE | 1 | Service part / kit | PartsGeek |
| 0C8526 | CARBURETOR (GT-990) | 1 | Service part / kit | PartsGeek |
| 0C8566 | SCREW HHFC M6-1.0 X 20 G8.8 | 16 | Service part / kit | PartsGeek |
| 0C8808 | HOOK, LIFTING | 2 | Service part / kit | PartsGeek |
| 0D2157 | SCREW SHC M6-1.0 X 50 C8.8 | 4 | Service part / kit | PartsGeek |
| 0D2274 | RETAINER, VALVE SPRING | 4 | Service part / kit | PartsGeek |
| 0D2774B | BASE, AIRBOX | 1 | Service part / kit | PartsGeek |
| 0D2775 | COVER, AIRBOX | 1 | Service part / kit | PartsGeek |
| 0D2930 | VALVE, SUMMER / WINTER | 1 | Service part / kit | PartsGeek |
| 0D3867 | SPRING, VALVE | 4 | Service part / kit | PartsGeek |
| 0D3961 | ASSEMBLY, CONNECTING ROD (GT-760) | 2 | Service part / kit | PartsGeek |
| 0D3998 | NUT HEX M8-1.0 G8 YEL CHR | 4 | Service part / kit | PartsGeek |
| 0D4012 | KIT BREATHER ASSEMBLY | 1 | Service part / kit | PartsGeek |
| 0D4015 | KIT OIL RELIEF | 1 | Service part / kit | PartsGeek |
| 0D4040E | ASSEMBLY, CRANKSHAFT HORIZONTAL DIRECT DRIVE (GT-990) | 1 | Service part / kit | PartsGeek |
| 0D4041 | ASSEMBLY, CAMSHAFT & GEAR | 1 | Service part / kit | PartsGeek |
| 0D4122E | ASSEMBLY, CRANKSHAFT HORIZONTAL DIRECT DRIVE (GT-760) | 1 | Service part / kit | PartsGeek |
| 0D4183 | ADAPTOR, SPIT BACK | 1 | Service part / kit | PartsGeek |
| 0D4522 | CONTROLLER ASSEMBLY | 1 | Service part / kit | PartsGeek |
| 0D4612 | SNORKEL, AIR INTAKE | 1 | Service part / kit | PartsGeek |
| 0D4788 | PLUG STD PIPE 3/8 STEEL SQ HD | 2 | Service part / kit | PartsGeek |
| 0D5014A | KNOB, AIRBOX 17mm | 1 | Service part / kit | PartsGeek |
| 0D5014B | KNOB, AIRBOX 95MM | 1 | Service part / kit | PartsGeek |
| 0D5125 | SPRING, WINTER/SUMMER VALVE | 1 | Service part / kit | PartsGeek |
| 0D5269 | ROCKER, COVER | 1 | Service part / kit | PartsGeek |
| 0D5313 | ROCKER ARM | 4 | Service part / kit | PartsGeek |
| 0D6007 | KIT PISTON & RINGS | 1 | Service part / kit | PartsGeek |
| 0D6008 | KIT GEAR COVER | 1 | Service part / kit | PartsGeek |
| 0D6020 | STUD M6-1.0 X 73 | 1 | Service part / kit | PartsGeek |
| 0D6021 | STUD, METRIC | 4 | Service part / kit | PartsGeek |
| 0D6024 | PLATE, PUSH ROD GUIDE | 2 | Service part / kit | PartsGeek |
| 0D6143 | TUBE, HEAT RISER 50.8 I.D. | 1 | Service part / kit | PartsGeek |
| 0D8059 | CARBURETOR (GT-760) | 1 | Service part / kit | PartsGeek |
| 0D8067A | ASSEMBLY, HEAD #1 | 1 | Service part / kit | PartsGeek |
| 0D8067B | ASSEMBLY, HEAD #2 | 1 | Service part / kit | PartsGeek |
| 0D8675A | KIT HEAD ASSEMBLY CYLINDER 1 | 1 | Service part / kit | PartsGeek |
| 0D8675B | KIT HEAD ASSEMBLY CYLINDER 2 | 1 | Service part / kit | PartsGeek |
| 0D9099-B | Remote Panel Plug-in Receptacle | 1 | Service part / kit | PartsGeek |
| 0D9853D | PUSHROD 144.6 | 4 | Service part / kit | PartsGeek |
| 0F8418 | System Fuse | 1 | Service part / kit | PartsGeek |
| 0F8419 | Assy: System Fuse | 1 | Service part / kit | PartsGeek |
| 0J9943Y12 | Automatic Standby Generator Owner’s Manual | Service part / kit | PartsGeek | |
| 72486-000 | 12 Volt DC Outlet | 1 | Service part / kit | PartsGeek |
| 72532-000 | 120 Volt AC Outlet | 1 | Service part / kit | PartsGeek |
Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Fuel consumption
| Rating | Load | L/h | gal/h |
|---|---|---|---|
Available documents
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