Generac Power Systems GTH - 990

Owner’s Manual
GTH - 990, 33 HP
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Generac Power Systems GTH - 990 Specifications

General

Cylinder Block	Cast Iron
Number of Cylinders	2
Oil Capacity	1.9 L
Engine Speed	3600 RPM
Cooling System	Air Cooled
Spark Plug	NGK BPR

Summary

Safety Rules

DANGER! HIGH OPERATING SPEEDS

Warning against tampering with engine governed speed due to dangers and risks.

BEFORE OPERATING

Precautions for safe operation before starting the engine, including fuel handling.

WHILE OPERATING

Guidelines for safe operation while the engine is running, covering exhaust, cooling, and moving parts.

DANGEROUS ELECTRIC SHOCK WARNING

Warning about electrical shock hazards when working in wet conditions or barefoot.

CALIFORNIA PROPOSITION 65 WARNINGS

Warnings regarding carcinogens and reproductive harm from engine exhaust and product emissions.

WARNING! HOT ENGINE PARTS

Caution about hot engine parts like the muffler causing burns or fire hazards.

Service Information

General Information

OIL AND FUEL INFORMATION

Information on using the correct oil and fuel types, including cautions and recommendations.

RECOMMENDED OIL TYPE

Details on recommended oil weights (SAE 30, 10W-30, 5W-30) based on temperature.

RECOMMENDED FUEL TYPE

Specifies using clean, fresh, unleaded gasoline with a minimum of 85 octane.

ENGINE EMISSION COMPLIANCE PERIOD

Information on EPA requirements and components of the engine's emission control system.

RECOMMENDED BATTERY

Specifies 12-volt negative ground batteries with a minimum rating of 450 cold-cranking amps.

OPERATION AND MAINTENANCE

Outlines owner's responsibility for safety checks, prompt maintenance, and periodic engine checks.

BEFORE STARTING THE ENGINE

Tasks to perform before starting the engine, including checking and adding engine oil.

Checking and Adding Engine Oil

Step-by-step guide to checking and adding engine oil, emphasizing not to overfill.

Operation

STARTING THE ENGINE

Detailed steps for starting the engine, including choke and key operation.

STOPPING THE ENGINE

Steps to properly stop the engine, including removing load and turning the key off.

LOW OIL PRESSURE SYSTEM

Explains the function of the low oil pressure switch and its notification methods.

General Maintenance Recommendations

PERFORMING SCHEDULED MAINTENANCE

Emphasizes performing service as per the schedule for operation and emissions compliance.

CHECKING THE OIL LEVEL

Reminder to check oil level before each use or every 8 hours of operation.

Maintenance

Changing the Oil Filter

Step-by-step guide for removing and installing a new oil filter.

CLEANING INTAKE SCREEN AND COOLING FINS

Instructions to clean intake screen and cooling fins to prevent overheating and damage.

SERVICING THE AIR CLEANER

Importance of servicing the air cleaner system for engine performance and longevity.

CAUTION! AIR CLEANER SYSTEM

Warning against operating the engine without the complete air cleaner system installed.

Option 2: Air Cleaner Housing

Steps for cleaning the air cleaner housing and replacing the filter.

CLEANING SPARK ARRESTOR SCREEN

Instructions for inspecting and cleaning the spark arrestor screen, especially for specific land use.

ENGINE SPEED

Warning against adjusting engine speed; factory setting is recommended.

CARBURETOR ADJUSTMENTS

States carburetor is factory set and tampering violates regulations and voids warranty.

CHECKING AND ADJUSTING VALVE CLEARANCE

Procedure and schedule for checking and adjusting valve clearance for engine longevity.

CAUTION! VALVE CLEARANCE

Warning to disconnect spark plug wires before working on the engine.

MAINTENANCE SCHEDULE

Provides a schedule for periodic maintenance tasks based on hours or time.

STORAGE INSTRUCTIONS

Guidelines for preparing the engine for storage, including running time and fuel handling.

DANGER! FUEL STORAGE

Warning against storing engines with fuel indoors due to fire/explosion risk.

WARNING! FUEL DRAIN

Instruction to drain fuel outdoors away from open flames when the engine is cool.

Troubleshooting

PRODUCT SPECIFICATIONS

Lists key specifications of the GTH 990 engine, such as bore, stroke, and displacement.

OIL CAPACITIES

Provides oil capacity figures for the engine with and without an oil filter.

Engine Will Not Start; Or Starts and Runs Rough

Lists common causes and corrections for engine starting or running issues.

Engine Shuts Down During Operation

Lists causes and corrections for the engine shutting down unexpectedly during operation.

Engine Lacks Power

Lists causes and corrections for the engine not performing at full power.

Engine Hunts or Faults

Lists causes and corrections for the engine running erratically or unevenly.

Warranty

YOUR WARRANTY RIGHTS AND OBLIGATIONS

Outlines Generac's and owner's responsibilities regarding the Exhaust Emission Control System Warranty.

MANUFACTURERS WARRANTY COVERAGE

Details the duration and conditions of the ECS warranty for emission-related parts.

OWNERS WARRANTY RESPONSIBILITIES

Stresses owner's responsibility for completing maintenance and retaining records for warranty claims.

EMISSION CONTROL SYSTEM WARRANTY

Explains the applicability, coverage, and interpretation of the ECS warranty for emission-related parts.

EXHAUST EMISSION RELATED PARTS

Lists components that are considered part of the exhaust emission related system.

GENERAC POWER SYSTEMS TWO-YEAR LIMITED WARRANTY

Details the two-year limited warranty for GTH series engines, including repair or replacement.

THIS WARRANTY SHALL NOT APPLY TO THE FOLLOWING

Lists specific conditions, uses, or damages that are excluded from the warranty coverage.