Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns.
Portable generator troubleshooting quick reference guide
This troubleshooting guide is intended to be a quick reference guide for problem-to-issue identification and solution.
Environment
This article applies to most portable generators and is intended as only as a quick reference. Some features vary by unit and are indicated with (if equipped). If you are unsure whether your unit is equipped with a specific feature, please consult your owner's manual. See Where can I download a user manual for my Generac portable generator?
| Problem | Issue | Solution |
| Engine is running, but AC output is not available | | |
| | Circuit Breaker is OPEN | Reset Circuit Breaker |
| | Poor connection or defective cord set | Check and repair |
| | The connected device is bad. | Connect another device that is in good condition. |
| | GFCI receptacle is OPEN (if equipped) | Correct ground fault and press the reset button on GFCI |
| | Fault in the generator | Contact IASD |
| Engine runs well at no-load, but bogs when load is applied | | |
| | Short circuit in a connected load | Disconnect shorted electrical load. |
| | Generator is overloaded | Reduce load - See the owner's manual for generator limits. |
| | The engine speed is too slow. | Contact IASD |
| | Shorted generator circuit | Contact IASD |
| | Clogged carburetor | Clean carburetor |
| | Stale or old fuel | Replace with fresh fuel. |
| | Clogged spark arrestor | Clean spark arrestor screen |
| Engine will not start or starts and runs rough | | |
| | Fuel shut-off is OFF. | Turn the fuel shut-off ON. |
| | Dirty air filter | Clean or replace air filter(s) |
| | Out of fuel | Fill fuel tank |
| | Stale fuel | Drain the fuel tank and fill it with fresh fuel. |
| | The spark plug wire is not connected to the spark plug wire | Connect wire to spark plug |
| | Water in fuel | Drain the fuel tank and fill it with fresh fuel. |
| | Over choking | Set choke to no choke position. |
| | Low oil Level | Fill the crankcase to the correct level |
| | Bad spark plug | Replace spark plug |
| | Clogged carburetor | Clean carburetor |
| | Excessive rich fuel mixture | Contact IASD |
| | Intake valve stuck open or closed. | Contact IASD |
| | Engine lost compression | Contact IASD |
| Engine shuts down during operation | | |
| | Out of fuel | Fill fuel tank |
| | Low oil level | Fill the crankcase to the correct level |
| | Fault in engine | Contact IASD |
| | COsense™ shut-offs due to accumulating carbon monoxide if a red light blinks on the side panel badge | Follow safety Instructions and relocate the generator to an open area outside, far away from windows, doors, and vents. |
| | COsense™ shuts off due to a system fault if a yellow light blinks on the side panel badge. | Confirm that the yellow light blinks when the generator shuts off. If COsense™ continues to fault and shut off, contact IASD. |
| Engine lacks power | | |
| | Generator is overloaded | Reduce load |
| | Dirty air filter | Clean or replace the air filter |
| | The engine needs to be serviced. | Contact IASD |
| | Clogged spark arrestor | Clean spark arrestor screen |
| Engine surges or stumbles | | |
| | The choke is opened too soon. | Set the choke to a halfway position until the engine runs smoothly. |
| | Carburetor is running too rich or too lean | Contact IASD |
| | Bad spark plug | Replace spark plug |
| | Clogged carburetor | Clean carburetor |
| Engine starts and shuts off right away | | |
| | Low oil level | Fill the crankcase to the correct level. |
| | COsense™ shut offs due to accumulating carbon monoxide if a red light blinks on the side panel badge. | Follow safety Instructions and relocate the generator to an open area outside, far away from windows, doors, and vents. |
| | COsense™ shuts off due to a system fault if a yellow light | Confirm that the yellow light blinks when the generator shuts off. If COsense™ continues to fault and shut off, contact IASD |
| Pull cord keeps pulling loose , does not start the generator, and requires manually coiling | The recoil spring is damaged | Contact a local IASD. |
Terminology
Independent Authorized Service Dealer (IASD) - A certified service center authorized by Generac to perform warranty repairs on Generac products. These dealers are trained and equipped to service Generac equipment and use genuine Generac parts to perform repairs. See How Can I Find a Generac Service Dealer in My Area?
COsense™ - A carbon monoxide (CO) monitoring feature available on some Generac portable generators. It continuously monitors for any source of CO and automatically shuts off the generator if high CO levels are detected. This is an important safety feature to help protect against CO poisoning.
Ground Fault Circuit Interrupter (GFCI) - This safety feature helps protect against electrical shock hazards. GFCI protection is designed to shut off the circuit's power if a difference in current between the hot and neutral wires is detected, indicating that electricity is flowing through an unintended path.
Note: Units can have GFCI-protected outlets or full panel GFCI protection.
