Toro Lawn Mower Won’t Start: Why and How To Fix

Toro lawn mowers are one of the forefront lawn mower brands in the market. They are known for their durability, efficiency, and cut quality. They are very rugged and can last for over a decade with proper maintenance. They are a good investment if you are looking for something to serve for a long time. 

Just like any machine, lawnmowers encounter problems over time. You might experience your lawnmower just not starting, and it can be for several reasons, which this article will address and how to fix them. 

The most common peculiar to Toro lawn mowers refusing to start is a faulty carburetor, but it can also be a result of other issues such as electric system failure, a damaged spark plug, bad battery, carburetor issues, bad fuel, and many different reasons. Figuring out the particular problem can be exhausting, but not to worry, this article will guide you on how to diagnose the problem and fix your lawnmower to get cutting again. 

Below are possible reasons why your Toro lawn mower won’t start and how to fix it:

• A faulty or dirty carburetor
• Empty fuel tank 
• Using bad fuel
• Damaged spark plug
• Low compression
• Bad fuel pump
• Blocked fuel line and filter
• Bad battery and corroded battery components 
• Dirty air filter 

Faulty Carburetor 

A good carburetor is indispensable to an engine’s proper function. A carburetor’s function is to ensure that the right mixture of air and water is supplied to the engine cylinder for combustion. These symptoms indicate a faulty carburetor: exhaust pipe emitting black smoke,  overheating, stalling, backfiring, engine performance drops significantly, etc. If these problems occurred right before the lawnmower would not start, then the carburetor is the likely problem. To fix this requires replacing the old carburetor, usually.

How to fix

• Disconnect the spark plugs, and remove the air filter housing
• Drain the fuel tank into a container 
• Remove the blower housing to reveal the carburetor 
• Proceed to remove the carburetor and install the replacement
• Reassemble the lawnmower and try starting it. 

Having replaced the carburetor, the lawnmower should work fine. However, if this is not the case, other checks can diagnose the issue. 

Make sure to check with the manufacturer’s manual or an expert as lawnmower models vary and may have different ways of removing or installing the carburetor. 

Dirty Carburetor

Hard starting, flooding, and stalling are signs of a dirty carburetor. Too much dirt will hinder the passage of air and fuel and reduce the amount meant to supply the engine for operation. A build-up of debris and particles over time will clog the carburetor, making the lawnmower not start. To fix this, you need to clean the carburetor with carburetor spray. 

How to fix

• Remove the outer casing and air filter.
• Unbolt the carburetor and remove it from the fuel line. Make sure to have a container or cloth to catch any fuel spills. 
• Clean around the carburetor bowl using a carburetor cleaner, and undo the nut.
• Remove the bowl and clean the nut out. You can clean the nut by poking a wire into and around it. Also, spray the nut with a carburetor cleaner. 
• Spray the carburetor with the cleaning spray and clean the holes. Clean the carburetor out, ensuring the holes are free of debris.
• Assemble the part back together and try starting the lawnmower 

Empty Fuel Tank 

The issue may be just a simple case of an empty fuel tank. You may have exhausted your fuel and forgotten to refill. Check the fuel tank, and if it is empty, fill it with fresh gas. 

Bad Fuel 

The suitable ethanol level for a Toro lawnmower is less than 10%. The lower the ethanol, the better. Bad fuel can also result from water, getting into the fuel, low octane rating, lead, or just old fuel. Ethanol is a common culprit as it collects moisture, which leaves a sticky substance on evaporation that clogs and degrades the fuel system. 

How to fix 

Drain the fuel tank and replace it with fresh fuel, adding a fuel additive to help clean the fuel system and prevent future gumming and corrosion. 

Damaged Spark Plug  

The function of a spark plug is to trigger the air-fuel mixture in the engine cylinder. High voltage electricity at the spark plug tip triggers combustion right on time. 

Spark plugs need to be changed from time to time. Oil and carbon can accumulate, making the spark plug dirty. This can cause the engine to misfire and affect its starting. 

How to fix 

Make sure the engine is off and cool before removing the spark plug. Remove the spark plug and replace it with a new one. 

Low Compression 

An air leak in the lawnmower engine will lead to low compression and a loose spark plug. A lawnmower will not start without compression in all the cylinders. The standard compression in hot weather is 90 PSI and 100 PSI  for cold weather. PSI means the pounds per square inch, that is, the amount of pressure on a one square inch area. 

How to fix

• Check if the spark plug is loose and tighten it if so. 
• Replace faulty chamber components and gaskets. It is best to call an expert to handle this.
• Replace worn-out valves or piston rings 

Bad Fuel Pump 

The plastic and components of the fuel pump weaken over time and may not have the required pressure to pump gas. You have to check to see if the fuel pump is damaged, as it can be hard to tell. A common sign is when gas is leaking from the seams. To test, use the shut-off clamps to control fuel flow. Observe if or not fuel flows to the inlet of the fuel pump, then further check if the pump is pumping out fuel by removing the fuel hose from the carburetor and onto a container. Watch for a pulsating flow of fuel. If this does not happen, replace the fuel pump. 

Blocked Fuel Line and Filter  

A blocked fuel filter can result from dirt building up and hindering fuel flow. Signs of a clogged filter include stalling, smelly exhaust fumes, misfiring, and the case being addressed- refusal of the lawnmower to start. Check your fuel filter for clogging, and replace it with a new one if clogged. However, there are different types of fuel filters based on the material used in making them. Paper and nylon filters must be replaced, but metal fuel filters can be cleaned and reused. 

How to clean fuel filter 

• Park the mower on a flat, comfortable surface, and remove the fuel pump fuse. 
• Disconnect the spark plug to avoid fire hazards, the engine starting by itself, and other potential hazards
• Use a screw wrench to disconnect the fuel lines. An accidental fuel spill may occur here. Make sure to have a rag or container to catch the fuel if this happens. It is also advised to put on safety goggles to protect the eyes. 
• Remove the fuel filter and drain any fuel in it out. 
• Spray carburetor cleaner into and outside the filter. Tap the ends and leave to dry for about two hours, and reassemble. 

How to unclog the fuel line 

• Remove the fuel line.
• Spray some carburetor cleaning spray into the tube and blow into the passage, using compressed air till it is free of debris. 
• If unable to get it cleaned, it is best to replace it with a new fuel line. 

Bad Battery and Components  

Your toro lawn mower will not start if the battery is bad. The battery is what supplies power to the machine and needs to be in good condition for proper function. The battery itself may require replacement, the terminals have been corroded, or the cables lost. 

To clean corroded terminals, use a battery cleaner or a simple DIY mixture of baking soda and water with a brush and scrub the terminals till clean. Wipe off the terminals after cleaning with a cloth. 

To test your battery, use a multimeter. Any reading below 12.7 volts requires that the battery be charged. If you charge the battery but it does not hold, the best resort is to install a replacement. 

Dirty Air Filter  

Like the fuel filter, the air filter ensures clean air enters the combustion process. It filters particles from the air and collects them, which accumulate over time, blocking the filter. 

There are different types based on the material- foam, and paper. 

Foam filters can be washed and reused, while paper filters are best replaced. 

How to clean foam air filter  

• Remove the foam filter, and wash in dish soap or any mild detergent
• Rinse with water and sundry till it dries
• Coat the dry foam filter with a thin layer of oil to help it catch debris easily. 

Other factors can also be responsible for your Toro lawn mower’s refusal to start. Sometimes, the usage or maintenance procedure can be incorrect, making the lawn mower function improperly. Go through the manufacturer’s manual for directions specific to your lawnmower model in maintenance and operation. 

If, after running all the listed checks, the lawnmower still won’t start, it is best to let an expert diagnose and fix it.