Have you ever found yourself in the middle of a power outage, only to discover your Generac generator starts but won’t stay running? It’s frustrating, especially when you need it the most. You’re not alone—many people face this issue, and it can leave you feeling helpless and uncertain.
Key Takeaways
- Common Causes: The main reasons a Generac generator starts but won’t stay running include fuel supply issues, air intake problems, and electrical system failures.
- Troubleshooting Steps: Key checks involve ensuring adequate fuel levels, inspecting the battery condition, and verifying oil levels to prevent operational shutdowns.
- Preventive Maintenance: Regular servicing, maintaining cleanliness, and proper storage of the generator can greatly reduce the likelihood of stalling issues during power outages.
- Professional Help: Seek expert assistance if the generator persists in shutting down after initial troubleshooting, especially concerning ignition system or electrical issues.
- Safety Precautions: Always prioritize safety by addressing gas leaks or strange odors immediately and considering professional intervention for complex issues.
Common Causes of Generac Generator Starts But Won’t Stay Running
When your Generac generator starts but doesn’t keep running, several issues could be responsible. Understanding these causes helps in troubleshooting effectively.
Fuel Supply Issues
Fuel supply issues often cause generators to start briefly and then turn off. Check the fuel level first; a low fuel tank may prevent continuous operation. Next, inspect the fuel for contamination. Stale or dirty fuel can clog filters or injectors. Replace any clogged fuel filters and ensure the fuel line is free from leaks or kinks that restrict flow.
Air Intake Problems
Air intake problems can hinder proper combustion, causing the generator to stall. Verify that the air filter is clean and unobstructed. A dirty air filter restricts airflow, affecting the engine’s performance. If necessary, clean or replace the filter. Also, check for any obstructions in the air intake ducts that may prevent sufficient airflow.
Electrical System Failures
Electrical system failures can interrupt the generator’s ability to run smoothly. Inspect the battery for proper charge and connections. A weak or dead battery won’t sustain the electrical components needed for operation. Look for faulty wiring or loose connections in the starter circuit. Ensure the control panel is functioning correctly; issues here can also lead to stalling problems.
Troubleshooting Steps
If your Generac generator starts but won’t stay running, follow these troubleshooting steps to identify and resolve the issue.
Checking Fuel Levels
Check your fuel levels to ensure there’s enough gasoline in the tank. Low fuel can cause the generator to start briefly and then shut off. Confirm the fuel is clean and free of contaminants. Stale or old fuel can also affect performance, so replace it if it’s been sitting for more than 30 days. Use fresh fuel to ensure optimal operation.
Inspecting the Battery
Inspect the battery for charge and condition. A weak or dead battery can prevent the generator from running consistently. Measure the voltage using a multimeter; it should read at least 12.6 volts for a fully charged battery. Look for any corrosion at the terminals, as this can interrupt the electrical connection. Clean any corrosion using a mixture of baking soda and water, then reconnect the cables securely.
Examining the Oil Level
Examine the oil level to ensure it’s at the recommended level. Low oil can trigger a low-oil shutdown feature, stopping the generator to prevent damage. Check the oil using the dipstick; it should be within the designated range. If oil levels are low, top up with the appropriate type for your generator model. Regularly change the oil according to the manufacturer’s guidelines to maintain performance.
Preventive Maintenance Tips
Regular maintenance ensures your Generac generator runs smoothly and reliably. Following these preventive measures can help avoid start-and-stop issues during power outages.
Regular Servicing
Schedule regular servicing every 12 months or after every 100 hours of operation. During servicing, a technician can check key components like the spark plugs, fuel filter, and battery connections. Replacing worn or damaged parts promptly prevents bigger problems. Keep a maintenance log to track service dates and tasks performed.
Keeping the Generator Clean
Keep your generator clean to enhance performance and longevity. Dust and debris can clog vents and filters, impairing airflow. Wipe down the exterior with a damp cloth and clean the air filter every month. If the generator is exposed to elements, consider using a cover to shield it from dirt, moisture, and UV rays.
Ensuring Proper Storage
Store your generator in a dry, well-ventilated area. If you plan to store it for an extended period, drain the fuel system to prevent any stale fuel issues. Consider using fuel stabilizers to maintain fuel quality. Inspect the generator periodically during storage to ensure no pests or rust develop.
When to Seek Professional Help
Recognizing when to involve a professional can save time and prevent further complications with your Generac generator. If you’ve completed initial troubleshooting steps and the issue persists, consider the following situations for seeking expert assistance.
Persistent Failure to Start
If your generator starts but shuts down repeatedly, and you’ve checked the fuel, battery, and oil levels, a technician can conduct a more in-depth diagnosis. Specialists are equipped to look at internal components that could cause ongoing issues.
Ignition System Problems
When you’ve confirmed clean fuel and a charged battery, problems in the ignition system may exist. Technicians can test the ignition coil, spark plugs, and related wiring for faults. These components might require professional servicing or replacement.
Fuel Delivery Issues
If low-quality or contaminated fuel is suspected and you’re unable to resolve the issue, professionals can flush the fuel system. They can also address any damage caused by old or improper fuel.
Electrical System Concerns
When wiring issues or faulty connections arise, professional help ensures safe repair. Your generator’s electrical system is complex, and attempting repairs without expertise may lead to further complications.
Frequent Faults After Maintenance
If your generator consistently exhibits these problems shortly after routine maintenance, it might be time for a service call. A professional can review servicing logs, identify maintenance oversights, and recheck critical components.
Safety Precautions
When tackling generator issues, keep safety a priority. If you encounter any gas leaks, strange odors, or other safety hazards, contacting professionals immediately is necessary. They can resolve risks effectively and ensure proper safety protocols.
Recognizing these signs can help you take appropriate action, getting your generator back to optimal performance without risking personal safety or equipment damage.
Conclusion
Dealing with a Generac generator that starts but won’t stay running can be frustrating. By following the troubleshooting steps and preventive maintenance tips outlined, you can keep your generator in top shape and ready for any power outage.
Regular checks on fuel levels air filters and battery condition can make a big difference. If you find yourself stuck despite your best efforts don’t hesitate to reach out to a professional. They can help you get back on track and ensure your generator runs smoothly when you need it most. Remember staying proactive is key to avoiding future problems.
Frequently Asked Questions
Why does my Generac generator start but not stay running?
Generators may start but fail to stay running due to fuel supply issues, air intake blockages, or electrical system failures. Check your fuel level, inspect the air filter, and examine the battery and wiring.
How can I troubleshoot my Generac generator?
To troubleshoot, start by checking the fuel level for clean gasoline. Inspect the battery for a good charge and ensure the oil level is adequate. Additionally, keep the air filter clean and look for any visible signs of wiring issues.
What maintenance do I need to perform regularly?
Regular maintenance includes scheduling serviced checks every 12 months or after 100 hours of operation. Replace spark plugs and fuel filters and ensure that the generator is clean and free of dust and debris.
How should I store my Generac generator?
Store your generator in a dry, well-ventilated area. Drain the fuel system for long-term storage and use fuel stabilizers to maintain fuel quality. Regular inspections during storage can help mitigate issues like pests or rust.
When should I seek professional help for my generator?
Seek professional help if your generator persists in failing after basic troubleshooting. Consider contacting a technician for ignition issues, fuel delivery problems, or electrical concerns, and immediately reach out for gas leaks or safety hazards.

Jake Newman is Appliance Mastery’s expert on refrigeration and cooling systems. With over a decade of experience in the appliance repair industry and certification from NASTeC, Jake is a trusted source of knowledge for homeowners who want to troubleshoot and repair their fridges, freezers, and air conditioning units.