MTD lawn mower won’t start. If your Lawn Mower is not starting up, there might be a problem with the plug, use a wire brush to clean it and reattach it. In some parts of the country.
You’ll need to add ethanol or marine fuel stabilizer especially if you’re going to be storing your mower during the winter months.
You may want to look into getting an ethanol-free fuel additive especially if you’re mowing thick grass in moist conditions so that it doesn’t gum up your machine’s engine. If however, none of these tips work then you probably need a new spark plug.
MTD lawn mower won’t start
There is a possibility that the above problems were caused by mechanical failure caused by excessive wear and tear over time. Consider replacing worn parts before throwing the machine away.
Below are some more common reasons and tips for why your MTD lawn mower won’t start.
Clogged carburetor
It’s time to clean the carburetor since it might be clogged. This is usually caused by leaving fuel in the lawnmower for a long period of time, leaving behind a thicker substance that gradually blocks the carburetor.
When this happens you may waste a lot of time trying to start your appliance as you will be unable to provide the engine with a sufficient amount of fuel.
If this is happening, use a carburetor cleaner to solve the problem. If it continues to happen, then buy or build another one since this issue could become very irritating over time.
Spark plugs are faulty
Look for signs of damage or wear on the spark plug. If it has carbon buildup, cracked porcelain, or a defective electrode, get a new one.
When you start your engine, you should see a strong spark between the tester’s terminals. You will have to replace the plug if this doesn’t happen because of wear and tear.
Fuel pump not working properly
The fuel pump has three ports: a gas in port, a gas out port, and a pulse port. The engine crankcase is connected to the pulse port via a small rubber tube. The rubber tube inside the crankcase is alternately pressurized and depressurized as the engine runs.
A diaphragm within your lawnmower fuel pump pumps this rubber tube into your lawnmower when pressure is applied. By overfilling your lawn mower engine oil, oil can enter your fuel line system through the rubber tube, causing the fuel to not pump correctly.
The fuel pump has two other check valves that are installed on either end of the input and output ports to ensure no fuel ever enters or leaves your automobile again.
These check valves can fail as well so if any kind of malfunction happens make sure to inspect both ends for damages before eventually replacing them with brand new ones.
The clogged fuel filter
If a lawnmower won’t start, you might have a clogged fuel filter. Most fuel filters are located inside the engine’s airbox or in an area under the rear of the seat.
In order to see if it is clogged, smell the old fuel stored in your tank. If it smells like gasoline but has a strong oily component to it, instead of getting just a hint of gas fumes when you smell the exhaust, this could be an indication that there is something sticky about your fuel.
If a clogged fuel filter is suspected, remove and clean it with carburetor cleaner and then replace it back into its place under the seat in order for your lawnmower to run smoothly again.
The rewind spring may be broken
It may be necessary to replace the recoil starter. The engine won’t start if the starter rope cannot be recoiled by the spring.
To replace a broken recoil start, unscrew three screws and remove it from its housing, being careful to set these parts aside so you don’t lose them. Replace broken part with new one and reassemble.
Recoil starter assembly doesn’t work 
The recoil starter assembly activates the engine by causing it to start spinning via turning the crankshaft. If your recoil starter assembly is faulty, you won’t be able to get the engine to start.
Remove the starter assembly and inspect it in order to determine if it can be repaired or needs replacing instead.
The key to testing a functioning recoil starter is that when you pull on it, tabs extending from the pulley and cam should grab onto an engine hub in such a way that causes it to fire up instantly when you release your hold on the starter cord.
The alternative option if you can’t do either of these things using a healthy induction system, this alternative method might serve as a lifesaver.
Flywheel key broken
Shearing has caused the flywheel to shatter in half. Power for the lawn mower’s engine is provided by the flywheel, which is a white ring that spins on the crankshaft.
If you run over a hard object, this piece of plastic may be damaged. In the event that your lawnmower suddenly stops after hitting an object, there’s a good chance that the flywheel has been damaged, which means the engine needs to be replaced.
Problem with Start and Safety Switches
To determine if the start switch and safety switch are defective, use a multimeter to test it for continuity. Replace both switches.
