Portable generator won’t start? Don’t panic – here's 9 common reasons why your generator’s engine won't start, and how to fix it.

9 Reasons Why Your Generator Won’t Start

1. It’s Out Of Fuel

While it may seem obvious, your generator’s fuel levels should be the first thing you check. If fuel levels are low, add more fuel to the tank.

Keep in mind that ‘stale’ fuel older than 30 days old can damage the fuel tank and may cause the generator to not start.

2. It’s Low On Oil

Most generators have a sensor to alert you when oil levels are low. However, if the spark plug is properly gapped and still not igniting, your low-oil sensor may be busted.

What To Do

Be sure to check your generators oil levels with a dipstick. If the oil is low, refill it with the specific oil type recommended by your manufacturer.

Note: Running the generator on an angled surface may trigger the low oil sensor even if there is enough oil.

3. The Spark Plug Is Damaged

A dirty or damaged spark plug may be preventing your generator from starting.

What To Do

To check your generator’s spark plug, remove it from the engine with a spark plug socket. If the spark plug is dirty, clean it carefully and clear away any signs of dirt and debris. Replace the spark plug if you notice any cracked porcelain or broken electrodes.

Then check the spark plug is working by holding it against the engine’s crankcase while pulling the recoil starter. If it’s working, you’ll see blue sparks.

4. The Fuel Valve Is Clogged

If you have a full tank of fuel but the generator still won’t start, there may be a problem with the fuel valve or fuel line.

What To Do

Ensure the fuel valve is set to open when starting your generator. If the generator still won’t start, open the vacuum relief valve on the top of the fuel tank. Then, unplug the outlet hose from the intake side of the fuel valve to see if fuel is flowing freely.

If your generator has an in-line fuel filter between the fuel valve and carburetor, be sure to check that as well for any blockages.

5. The Choke Lever Is In The Wrong Position

If your generator sounds like it’s trying to start, but just won’t turn over, the choke lever may be in the wrong position.

What To Do

When cold starting the generator, the choke lever should be completely closed. Then, gradually open the choke lever as the generator warms up.

Alternatively, if you’ve been using the generator and only turn it off briefly, the choke lever will need to be halfway or fully open in order to restart the generator.

6. The Carburetor Is Blocked

If your generator has been in storage, it’s likely your carburetor could be blocked with old, sticky fuel.

What To Do

As a solution, shut off the fuel valve and open the carburetor drain at the bottom of the carburetor’s bowl. If the generator still won’t start, remove the entire bowl from the bottom of the carburetor and clean out any old fuel.

To avoid this in future, follow portable generator storage best practices such as draining the fuel tank and carburetor beforehand.

7. The Battery Is Flat

Just like your car, generator batteries lose charge over time due to lack of use. So, if your generator has an electric push-button or remote start, the battery may be flat.

What To Do

To recharge the battery, try starting the generator using the backup pull starter. If this doesn’t work or your generator doesn’t have a pull starter, try charging it with a 12-volt DC outlet or jump starting it from your car.

8. You Have Items Plugged Into The Generator

You should never have anything plugged into the generator when starting- this includes vacant extension cords.

9. The Air Filter Needs Replacing

A clogged air filter may prevent the necessary amount of air entering the carburetor for ignition.

What To Do

To check the filter, open up the air filter compartment on the side of the generator and check the air filter element inside. Clean or replace if necessary.

Get The Right Advice, Contact Us Today

If you’re still unsure, it’s always best to contact an expert.

With years of experience, you can rely on Blue Diamond Machinery to provide the right advice and a generator to meet your unique charging requirements.

For more information on the best model to suit your power requirements, contact us today or speak to one of our expert team on 1300 998 647.