Generator won’t start

Generator Won’t Start – Step by Step Troubleshooting

Generators are valuable assets that provide backup power during outages and are essential for various applications, from camping trips to emergency situations. However, like any machinery, generators can sometimes refuse to start, leaving you in the dark.

When your generator won’t start, it can be frustrating and concerning, but fear not.

In this comprehensive guide, we’ll walk you through the step-by-step troubleshooting process to diagnose the issue and get your generator up and running again. Whether you’re a seasoned generator owner or a newcomer, this guide will equip you with the knowledge and skills to tackle generator start-up problems effectively.

Why Won’t My Generator Start?

Before delving into the troubleshooting steps, let’s understand some common reasons why your generator may refuse to start:

  1. Fuel Issues: One of the most frequent culprits is fuel-related problems. It could be as simple as an empty fuel tank, stale fuel, or a clogged fuel filter.
  2. Battery Problems: Electric start generators rely on batteries to initiate the engine. A dead or discharged battery can prevent your generator from starting.
  3. Oil Level: Generators have a safety feature that prevents starting if the oil level is too low. Ensure the oil level is adequate.
  4. Spark Plug Troubles: A faulty spark plug can hinder ignition. Check for fouled or damaged spark plugs.
  5. Choke Position: If your generator has a choke, it must be in the correct position for starting.

Troubleshooting Your Generator Won’t Start

Now, let’s go through a systematic troubleshooting process to identify and resolve the issue:

1. Fuel Check

  • Step 1: Ensure there’s an adequate amount of fuel in the tank. Low or empty tanks are common causes of non-starting generators.
  • Step 2: Confirm the fuel valve or switch is in the “On” position.
  • Step 3: Check for stale fuel. If the fuel has been sitting for an extended period, it might be unusable. Drain the old fuel and replace it with fresh gasoline.
  • Step 4: Inspect the fuel filter. A clogged filter can impede fuel flow. Replace it if necessary.

2. Battery Inspection

  • Step 1: Check the battery’s voltage with a multimeter. It should read at least 12.6 volts for a 12-volt battery.
  • Step 2: Clean the battery terminals and connectors to ensure a good connection.
  • Step 3: If the battery voltage is low, charge it with an appropriate battery charger.
  • Step 4: If the battery is old or unable to hold a charge, consider replacing it.

3. Oil Level

  • Step 1: Check the oil level by removing the dipstick, wiping it clean, and reinserting it. Then, remove it again to check the oil level. Add oil if it’s below the recommended level.
  • Step 2: Refer to your generator’s manual for the correct oil specifications.

4. Spark Plug Examination

  • Step 1: Locate the spark plug, usually near the engine’s front. Remove it with a spark plug wrench.
  • Step 2: Inspect the spark plug for fouling, damage, or excessive carbon buildup. Clean or replace it if necessary.
  • Step 3: Ensure the spark plug gap matches the manufacturer’s specifications. Adjust it if needed.

5. Choke Position

  • Step 1: If your generator has a choke, ensure it’s in the “Choke” or “Closed” position for a cold start.
  • Step 2: After a few attempts, move the choke to the “Run” or “Open” position to prevent flooding.

6. Air Filter Inspection

  • Step 1: Locate the air filter housing, usually on the side of the engine.
  • Step 2: Remove the air filter cover and inspect the filter. A dirty or clogged air filter can restrict airflow to the engine, affecting starting.
  • Step 3: Clean or replace the air filter if it’s dirty or damaged.

7. Check for Spark

  • Step 1: If your generator still won’t start, check for a spark at the spark plug.
  • Step 2: Remove the spark plug and reconnect it to the spark plug wire.
  • Step 3: Ground the spark plug against the engine’s metal surface.
  • Step 4: Crank the generator while observing the spark plug’s electrode. You should see a visible spark. If not, there may be an issue with the ignition system that requires professional attention.

8. Fuel System Cleaning (If Necessary)

  • Step 1: If the generator has been sitting idle for an extended period or if you suspect fuel system issues, consider cleaning the carburetor.
  • Step 2: Consult your generator’s manual for carburetor cleaning instructions or seek professional assistance.


Troubleshooting a generator that won’t start can be a manageable task, and in many cases, the issue is easily resolved. By following the steps outlined in this guide, you can diagnose and address common problems preventing your generator from starting.

However, if you encounter issues that are beyond your expertise or the generator remains non-starting, it’s advisable to seek professional assistance to avoid further complications.

Remember that regular maintenance and proper storage practices can help prevent many of these starting issues in the future, ensuring your generator is always ready when you need it.

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