Generac Power Systems GTH990 Manuals

Manuals and User Guides for Generac Power Systems GTH990. We have 3 Generac Power Systems GTH990 manuals available for free PDF download: Service Manual, Engine Parts Manual

Generac Power Systems GTH990 Service Manual (77 pages)

OHVI V-TWIN ENGINE

Brand: Generac Power Systems | Category: Engine | Size: 15.95 MB

Table of Contents
3
Rules for Safe Operation
4
- Before Operating
  4
- While Operating
  5
- Service Information
  5
- Intake
  6
- Ignition and Power
  6
- Compression
  6
4-Cycle Engine Theory
6
- Maintenance Schedule
  7
- Lubrication
  7
- Recommended Oil Type
  7
Section 1: General Information
7
- Change Oil Filter
  8
- Oil Fill/Check Vertical Engine
  8
- Cleaning Intake Screen
  8
- Oil Filter
  8
- Replace Spark Plugs
  9
- Service Canister Air Cleaners
  9
- Air Cleaner Maintenance
  9
- Service Dual Element Air Cleaners
  9
- Troubleshooting
  10
- Check Ignition
  10
- Engine Running
  10
- Systematic Check
  10
Section 2: Ignition
10
- Cylinder Balance Test
  11
- Cylinder Leak down Test Procedure
  11
- Cylinder Leakdown Test
  11
- Check Compression
  11
- Equipment Affecting Engine Operation
  12
- Hard Starting or will Not Start
  12
- Things Which Affect both Cylinder
  12
- Engine Won't Stop
  12
- Engine Wiring Harness
  13
- Testing Ground Wires
  13
- Digital Multimeter
  13
- Diode Failure Diagnosis
  13
- Removing and Installing Wire Harness
  14
- Ignition
  14
- Ignition Coil Testing
  14
- Wire Harness Check
  14
- Ground Wire Routing
  15
- Adjust Ignition Coil Air Gap
  15
- Remove Flywheel
  15
- Adjusting Air Gap
  15
- Removing Flywheel
  16
- Torquing Flywheel Nut
  16
- Check Flywheel and Crankshaft
  16
- Installing Flywheel and Fan
  16
- Vertical Shaft Carburetor
  17
- Carburetor Removal
  17
- Horizontal Shaft
  17
- Carburetor Types
  17
Section 3: Carburetion and Fuel System
17
Section 4: Governor Controls and Governor
29
- Governor Arm
  30
- Governor Arm Assembly
  30
- Crankcase Bolt Torque Sequence
  30
- Static Governor Adjustment (Later Version)
  31
- Dynamic Governor Adjustment (Earlier Version)
  31
- Dynamic Governor Adjustment
  31
- Static Governor Adjustment
  31
- Remove Cylinder Heads
  33
- Remove Rocker Arms
  33
Section 5: Cylinder Head and Valves
33
- Disassemble Cylinder Head
  34
- Remove Cylinder Head
  34
- Removing Retainers
  34
- Removing Valve Stem Seals
  34
- Inspect and Repair
  35
- Reface Valves and Seats
  35
- Check Cylinder Head Distortion
  35
- Valve Seat Dimensions
  35
- Install Valves
  36
- Check Valve Springs
  36
- Measure Valve Stem Diameter
  36
- Install Valve Stem Seals
  36
- Compress Valve Spring and Install Keepers
  37
- Adjust Valve Clearances
  37
- General Assembly
  38
- Engine will Not Crank
  39
- Starter Motor Spins but Does Not Crank Engine
  39
- Starter Motor Spins but will Not Stop
  39
- Engine Cranks Slowly
  39
Section 6: Electric Starter
39
- Testing Starter Voltage Drop
  40
- Checking Starter Voltage Drop
  40
- Test Starter Motor
  40
- Testing Starter Solenoid
  40
- Starter Amp Draw Test
  41
- Battery Information
  41
- Testing Starter Motor Performance
  41
- Typical Battery
  41
- Checking Battery
  42
- Testing Battery
  42
- Battery Recommendations
  42
- Battery Cable Recommendations
  42
- Vertical Shaft
  43
- Testing DC Output Charging Wire
  47
- Testing AC Output
  47
- 20 Amp Regulated Alternator
  47
- Alternator Output Test
  47
Section 7: Alternators
47
- Batteries
  48
- Basic Charging System Schematic
  48
- Amp Alternator
  48
- Protection Systems
  49
- Checking the Engine Oil Level
  49
- Engine Protective Devices
  49
- Low Oil Pressure Switch
  49
- Oil Change Procedure
  50
- Removal of Oil Filter
  50
- Oil Drain Location
  50
- Changing the Engine Oil and Filter
  50
Section 8: Lubrication System
50
Section 9: Engine Disassembly
53
Section 10: Cylinder and Crankcase Cover
55
- Bearings
  56
- Cylinder Cross Hatch
  56
- Honing Cylinders
  56
- Check Magneto (Flywheel End) Bearing
  56
- Check Pto Bearing
  57
- Check Camshaft Bearings
  57
- Install Pto Oil Seal
  57
- Oil Seals
  57
- Honing Fixture
  58
- Check Camshaft:
  59
- Check Crankshaft:
  59
Section 11: Crankshaft and CAMSHAFT
59
- Disassemble Piston and Connecting Rod
  61
- Checking Piston and Rings
  61
- Check Ring Grooves
  61
- Remove Rings
  61
- Checking Ring End Gap
  62
- Check Piston Pin Bore
  62
- Check Piston Pin
  62
- Check Rod Bearings
  62
- Assemble #1 Rod and Piston
  63
- Assemble #2 Rod and Piston
  63
- Piston Ring Installation
  63
- Torque Connecting Rods
  65
- Install Crankshaft
  65
- Installing Piston and Connecting Rod
  65
- Compressing Rings
  65
Section 13: Engine Assembly
65
- Installing Camshaft
  66
- Crankcase Oil Passage O-Ring
  66
- Rotating Governor Shaft
  66
- Installing Oil Pump
  66
- Crankcase Screw Torque Sequence
  67
- Install Alternator
  67
- Install Coils
  67
- Install Breather
  67
- Install Rocker Arms
  68
- Adjust Air Gap
  68
- Install Cylinder Head
  68
- Torque Flywheel Nut
  68
- Adjust Valve Clearance
  69
- Install Valve Covers and Gaskets
  69
- Install Blower Housing
  69
- Ground Terminal
  70
- General Specifications
  71
- Common Specifications
  71
- Torque Specifications
  71
Section 14: Specifications
71
Standard and Reject Dimensions
72

Generac Power Systems GTH990 Service Manual (74 pages)

Brand: Generac Power Systems | Category: Engine | Size: 17.31 MB

Generac Power Systems GTH990 Engine Parts Manual (8 pages)

Brand: Generac Power Systems | Category: Engine | Size: 1.8 MB

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