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.