Your lawn mower has been sitting for a period of time and now it won’t start. When your lawn mower sits for a period of time, certain parts may need to be cleaned, tightened, or replaced. There are many reasons a lawn mower will not start including old fuel, a bad spark plug, electrical issues, etc. You may have left the gas in the mower from the last time you mowed and it is no longer usable. We will list the 5 most common reasons why your lawn mower will not start and how to fix it! These NO START methods are for all lawn mowers including Craftsman, Honda, Troy-Bilt, Lawn-Boy, AAVIX, Yard Machines, Poulan Pro, Husqvarna and Briggs & Stratton.
Gas Lawn Mower Will Not Start
5 Things To Check To Get It Running
5 Common Reasons Why Your Lawn Mower Will Not Start:
1 – Lawn Mower Gas Tank Is Empty?
Problem: The fuel tank on your lawn mower is empty. (Small amount of fuel may have evaporated from the year or season before)
Solution: Fill your lawn mower gas tank with new fuel and start it up.
2 – Old Fuel In Lawn Mower?
Problem: Gas from the last mowing season may have been left in the lawn mower gas tank.
Solution: Remove the old fuel by draining it out – Replace with new fresh gasoline and add some fuel system cleaner to the new gas – Start mower.
NOTE: By adding some fuel system cleaner to the new gas, this will remove any gunk or debris in the fuel system and help your mower run smoother.
3 – Faulty or Dirty Spark Plug In Lawn Mower?
Problem: The spark plug that starts your lawn mower may be faulty and needs to be replaced, or loose and not making a connection, or it has dirt and debris on it and needs to be cleaned.
Solution: Clean and tighten the spark plug – Or change out the old spark plug with a brand new one – Be sure to clean where the new spark plug is going to be installed in case there is dirt or debris buildup. Install the new spark plug or clean the old spark plug and start mower.
Small Engine (Lawn Mower) Replacement Spark Plug
Lawn Mower Replace Engine Spark Plug
Where Is Spark Plug Located On Lawn Mower
4 – Lawn Mower Air Filter Clogged?
Problem: Air filter on lawn mower is dirty – clogged – caked with grass.
Solution: Clean off the old air filter or buy a new air filter cartridge – This is to let your lawn mower get the proper amount of air into the intake to run smooth.
Lawn Mower Air Filter Cartridge
5 – Fuel Not Getting To Engine – Carburetor Or Fuel Filter?
Problem: Gas is not getting to the lawn mower engine and therefore it will not start.
Solution: The carburetor can be checked or simply tap on the side of it to attempt to let the fuel flow – You may need to also check the fuel filter to see if it is clogged and needs to be replaced. If the fuel filter is clogged, the engine will not receive gas and the mower will not start. Replace the fuel filter and start the mower.
Fuel Filter For Lawn Mower Engines with Fuel Pump
New Lawn Mowers – Gas and Electric
Craftsman, Honda, Troy-Bilt, Lawn-Boy, AAVIX, Yard Machines,
Poulan Pro, Husqvarna and Briggs & Stratton Lawn Mowers.
Another more complex issue that may be causing your lawn mower to NOT START:
Remove the spark plug and check if it is wet with fuel. If it is wet with gas, then you know the lawn mower engine is receiving fuel. You may have an electrical issue. It may be a bad plug, ignition module, safety shutoff, or bad plug wire. If you find that the plug is completely dry then you will know it is not getting fuel. If this is the case, you should check the carburetor and clean it. Once the carburetor is completely clean and adjusted accordingly, start the mower.
Lawn Mower Carburetor
If you need some help getting your lawn mower running, let us know your issue below and we will be happy to help.
Written by Keith Schneerer
Certified Appliance Tech · Founder, RemoveAndReplace.com
Keith has spent 30+ years repairing machines, starting as a military mechanic and later maintaining food processing equipment before moving into appliance repair. He founded RemoveAndReplace.com to share field-tested repair advice.
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Brand new TB220 troy built self propelled 21 inch mower. Worked fine until my neighbor hit something, will not start again.
I have Briggs & Stratton lawn mower 14.5 ohv that turns over but wont crank.
We checked the spark plug it’s good, it’s wet, we checked the air filter, we replaced the coil pack thinking that would do the trick, but it’s something electrical, we’ve checked the switch that’s under the seat, what should I try next?
2013 Huskee LT 3800, MD# 13A276LF031 with Power More 420cc engine MD# 4P90JUB Riding lawn mower runs for approximately 10 t0 15 minutes before starving for gas and shutting off. I have replaced starter, carburetor with fuel solenoid, new Coil, fuel filter with arrow pointing towards the motor, new gas lines, new spark plug, gas tank with new breather attached, replaced oil filter and changed oil. New air filter. Not sure but think the kill switch wire from coil gets too hot lying on motor and shuts me down. HELP! Thanks