It can be very irritating when your lawn mower doesn’t start. This is a common problem that affects gas-powered mowers. You don’t need to buy a new mower before you know exactly what’s wrong. It could be something very simple you can fix on your own.
Most of the common causes why your lawn mower isn’t getting gas is because of a dirty carburetor, air filter, spark plug, out of gas, and many more. The only way to fix these issues is to clean or replace them and replace your fuel if it’s old.
Reasons why your lawn mower isn’t pumping gas
Gas-powered lawn mowers need fuel to be pumped into the carburetor to start and if there’s anything that is obstructing the flow of the fuel, your mower’s engine won’t start.
- Check the fuel tank
Always make sure you check if your lawn mower has enough gas before starting it. Also, check for holes on the tank’s cap that can create a vent that will allow air into the tank which will block the fuel from flowing to the carburetor. Remove any dirt and debris blocking the opening so you can restore the pressure needed to fuel the carburetor. Even when the tank is full, a small hole in the fuel cap can stop the flow of fuel and cause the engine not to start.
- Dirty air filter
The air filter in the carburetor cleans the air coming through of any dirt and debris that could damage the engine parts. With time, the air filter gets clogged up which affects the flow of air into your engine. When your engine doesn’t get enough air for fuel combustion, when the spark plug ignites, your mower doesn’t start.
- Clogged fuel filters
Fuel filters are meant to filter out all the sediment from the gasoline, but it can get clogged up from normal sediment or stale fuel that contains ethanol. The proper flow of fuel to the carburetor will prevent your mower from starting because the fuel doesn’t reach the spark plug. You should replace the fuel filters.
- Manual choke left turned on
The choke is a shat-mounted valve found in the carburetor in the air intake chamber. Its purpose is to block airflow to provide improved suction which will allow your engine to start easily. Some mowers have automatic chokes while others use the manual choke that you have to turn on and off. If you leave the manual choke on several times after starting your mower, your carburetor will likely flood up causing your lawn mower not to start.
- Dead battery
Batteries normally last a long time, but sometimes they’ll go dead without any warning. Always check your battery’s voltage to see if it’s lacking juice. If you have a 12V battery, check the voltage to see if it’s reading close to 12V, if it’s less it might not have enough juice to start your mower.
- Stale gas
Gas has a shelf life of about 30 days because it contains ethanol. If the gas in your tank is old, the ethanol can cause corrosion and clog your carburetor. Ethanol-containing gas can absorb water from the atmosphere which can cause the gas and ethanol to separate. When the ethanol has absorbed enough moisture and has sat in the tank for a while can block the fuel system and prevent your engine from starting.
- Dirty carburetor
The carburetor can also get dirty and clogged and old gasoline is the one thing that tends to gum up your carburetor. It develops skin or varnish that coats the inside parts and cleaning these parts using a carburetor spray cleaner will loosen and dissolve the gums and varnish. As you clean, check the inside parts for damage or wear, especially the float that rides up and down the carburetor. Ensure it’s moving freely and it’s not leaking so that gasoline flows properly in the carburetor.
Other reasons and solutions for your mower that won’t start
Check oil levels. Some mowers come with a low-level float switch that prevents your mower from starting
Starter rope issues
Check the flywheel brake to ensure nothing is jamming the blade
Something got tangled in the blades
The keys in the flywheel or the blade carrier mat have sheared or the internal surface of the blade carrier damaged requiring a replacement
Clogged main jet
Remove stuck dirt and debris or use a spray carburetor cleaner
How to fix a mower that’s not getting gas
- Replace fuel filter
If your mower won’t start, it’s most likely the fuel filters are clogged by fuel that has sat in the rank for a long time. The best option is to drain the old fuel from the tank and replace the fuel filters.
- Use fresh fuel
Old fuel tends to clog up the carburetor making it difficult for gasoline to flow so you should always ensure your tank has fresh gasoline. You can add a high-quality gas stabilizer to prevent the fuel from degradation by reducing oxidation to keep your store gas fresh for longer.
- Clean the carburetor
A clogged up carburetor from buildup debris can prevent the fuel from reaching the spark plug. Clean the carburetor by removing the fuel bowl and spraying the carburetor with a carburetor cleaner.
- Avoid high-ethanol gas
You should stick to using gasoline with less than 10% ethanol to prevent your carburetor from collecting atmospheric moisture that is absorbed by the high-alcohol fuel.
- Clean the spark plug
Your lawn mower not starting may be caused by a loose, dirty, or faulty spark plug that you can easily remove and clean or replace and also ensure it’s well fitted to prevent cut-offs or electric faults.
To ensure your lawn mower is always in top condition, you need to keep it well maintained. Poor maintenance causes most of the problems, so take time to properly clean its parts so they all work as expected.
Can you clean a carburetor without taking it apart?
Yes, you can clean the outside without disassembly, but the inside is what you need to clean the most so you must take it apart.
What happens if you leave gas in lawnmower over winter?
If you leave unused gas in your mower over the winter, it can get stale, gum up your carburetor, and invite rust.