bison logo

generator keeps shutting off: how to fix?

BISON will reveal common reasons why generators always shut down, guide you through the diagnostic workflow and provide practical solutions

Table of Contents

In a world where connectivity and productivity are non-negotiable, Portable generators emerge as the stalwarts of stability, especially in regions grappling with frequent power outages or in situations where consistent electricity is the lifeblood of critical operations.

However, imagine when a generator starts normally, runs for a few seconds or minutes and stops. This intermittent silence of a generator is not just an inconvenience; it’s a prelude to potential danger, disrupting businesses, affecting critical services, and in some cases, posing significant safety risks.

As this article progresses, BISON will reveal common reasons why generators always shut down, guide you through the diagnostic workflow and provide practical solutions to ensure your generator doesn’t leave you stranded when you need it most.

generator keeps shutting off how to fix

why does my portable generator keeps shutting off?

There are many parts inside a generator, which means there are many reasons why a generator always shuts down. To understand why a generator shuts down, you need to check some of the important parts of the generator one by one to find out what the problem is. Here are some of the most common causes.

fuel problems

One of the most common culprits behind generator shutdowns is fuel-related issues. These can manifest in several forms:

  • Contaminated fuel or water in fuel: Contaminated or poor-quality fuel can lead to incomplete combustion, precipitating a host of issues causing the generator to shut off. Similarly, water in the fuel can damage the engine and hinder performance.
  • Low fuel level and faulty fuel gauge: Sometimes, the issue is as straightforward as low fuel. A defective fuel gauge might indicate an inaccurate level, causing unexpected shutdowns.
  • Clogged fuel filter or lines: Over time, debris and dirt may clog the fuel filter or lines, hampering fuel flow and causing the generator to run rough or shut down.
  • Dirty carburetor or overflowing fuel level: A clogged carburetor affects the air-fuel mixture, disrupting optimal engine functioning. Similarly, an overflow, possibly due to a faulty float or stuck needle valve, can cause the carburetor to malfunction.


A generator may shut off to protect itself from damage when it overheats due to:

  • Lack of proper ventilation: Generators generate heat. Without proper ventilation, this heat can build up, leading the generator to overheat and shut off.
  • Cooling system malfunctions: This includes low coolant levels, ineffective fans, or a clogged radiator – all can cause the generator’s temperature to spike, pushing its thermal protection to trigger an automatic shutdown.
verify fuel level and quality

Battery and electrical system problems

Electrical issues can have a crippling effect on generator operation:

  • Dead or undercharged battery: A battery in poor health might not supply the necessary power to start the generator or keep it running.
  • Incorrect wiring or faulty components: Loose connections or defective components can disrupt the power flow, causing sudden shutdowns.

Engine and maintenance problems

Even with perfect fuel and impeccable electrical conditions, engine issues can still plague your generator:

  • Faulty spark plugs: Worn-out spark plugs can prevent efficient combustion, causing the engine to misfire or stall.
  • Overloaded generator: If the load exceeds the generator’s capacity, it might automatically shut down as a protective measure.
  • Dirty air filter: A dirty air filter restricts airflow to the engine, resulting in unpredictable shutdowns.
  • automatic Shut-Off System: Sometimes, the safety features designed to protect your generator cause shutdowns when they malfunction, causing them to “false positive” and shut off although everything is working fine.

how to fix a generator that keeps shutting off?

Fixing a generator that keeps shutting down depends on identifying the underlying problem. The following steps will guide you through the system diagnostic process to pinpoint the problem and possibly correct it, without requiring advanced tools or expertise.

verify fuel level and quality

Begin by ensuring that the generator has enough fuel. A generator unexpectedly shutting down can often be as simple as running on empty. Then, examine the fuel quality – stale or contaminated fuel can cause various engine issues leading to shutdowns.

check generator fuel

check oil level and condition

A generator may also turn off if there’s insufficient oil, or if the oil is dirty and viscous. Make sure the oil level meets the manufacturer’s suggested marks and that it appears clean and free of debris. Dark, thick, or foul-smelling oil could indicate it’s time to replace it.

remove and inspect spark plugs

Spark plugs are the workhorses of your generator’s engine. If a spark plug is coated in buildup or visibly damaged, it might not be able to ignite the fuel-air mixture properly, causing the generator to stall. Carefully remove and closely inspect the spark plugs for signs of wear or deposit.

clean air filter

Your generator needs to breathe. A clogged or dirty air filter restricts airflow, choking the engine and potentially causing it to shut off. Cleaning or replacing the air filter is an easy and inexpensive way to avoid this problem.

check fuel filters and lines for clogs

If the basic checks don’t uncover the issue, proceed to examine the fuel filters and lines. Clogged filters or lines obstruct fuel flow, forcing the generator to work harder until it finally gives up and shuts off. Cleaning or replacing them might restore your generator to good working order.

clean generator carburetor

look for signs of carburetor problems

A dirty or malfunctioning carburetor could easily spell trouble. Recognizable symptoms include difficulty starting, rough running, and sudden shutdowns. If a carburetor issue is suspected, a proper clean-up or overhaul may be necessary.

test oil pressure (if safe to do so)

For those with mechanical expertise—or with guidance from a professional—checking the oil pressure can reveal problems with the lubrication system. Note that this step should only be undertaken if you have the right tools and knowledge or under professional supervision, as it involves working with sensitive engine components.


While the unexpected shutdown of a generator can disconcert even the most well-prepared among us, knowledge of the problem’s roots can preempt such scenarios in the future.

At the heart of this reliability is proper maintenance and operation – two partners working hand in hand to ensure longevity and reliable service. Regularly monitor fuel, oil, air filter and spark plug condition; follow recommended oil changes and maintenance schedules to ensure the carburetor is clean and efficient and to avoid overloading. These are not just corrective actions.

They are a mantra for sustainable use of electricity and proof of proactive maintenance.

Invest in a reliable BISON generator

As we move from troubleshooting to taking decisive action, let us introduce you to the line of reliable and easy-to-maintain BISON generators.

Designed for precision and durability, BISON’s generators are a testament to seamless operation and powerful performance. They’re the power source that ensures your peace of mind, delivering power when you need it most without the threat of unplanned downtime.

Act now. Make sure your power stays on. Choose reliability. Choose excellence. Choose our generators.

contact us

Please complete our contact form and we will soon get back to you with expert advice.


Get in touch to speak with our experts!

enquire today

Speak with our sales manager today for additional information or an obligation-free quote.