Why Won’t My Troy Bilt Mower Start? 9 Reasons and Fixes

You’ve finally decided to mow your lawn. You move your mower onto the overgrown grass, ready to turn your lawn into neighborhood admiration. However, your Troy Bilt mower won’t start. To make it worse, you have no clue why your trusty mower has chosen today to fail.

A Troy Bilt mower can’t start because of a clogged carburetor, defective ignition coil/switch, clogged air filter, clogged fuel filter, insufficient gas, plugged gas cap, damaged spark plug, defective fuel pump, and clogged fuel line. We’ve encountered these problems ourselves and have learned the different causes and some handy fixes we will share with you today.

Clogged Carburetor 

When you start your mower, the gas and air must mix to allow combustion in the engine. When the carburetor is clogged, this process cannot occur, nor can your mower start.

Troy Bilt mower carburetors clog when you leave fuel in the mower for an extended time, resulting in a sticky residue. Dirt and debris may also find their way into the carburetor resulting in clogging.

To fix a clogged carburetor, clean with a carburetor cleaner. You can clean the carburetor without removing it. Spray the carburetor with a generous amount of cleaner. You may have to rebuild or replace the entire carburetor if cleaning does not unclog it.

Defective Ignition Coil/Switch

When the ignition switch becomes defective, your Troy Bilt mower won’t start. Ignition switches on lawnmowers can fail for various reasons, including faulty wiring or problems with the solenoid coil. When these are defective, electric signals cannot pass to the starting motor.

In addition to a lawn mower that won’t start, other tell-tale signs of a defective ignition switch include trouble mowing the ignition lever from OFF, RUN, or START positions and a sticking ignition key.

To fix the problem, check and fix any wiring that may have come off or loosened. If the problem is due to a worn-out ignition switch or components, find the right parts and replace them entirely.

Clogged Air Filter

A lawn mower that won’t start is a common sign of a clogged air filter. The air filter protects the internal engine of your mower from damage due to dirt and debris.

As the air filter accumulates more dirt, your lawn mower might overheat and stop working. You may notice a lot of black smoke from your exhaust or the engine sputtering. In some cases, it won’t start at all.

Fortunately, you can remedy this problem by cleaning the air filter. For paper air filters, tap the dust off or replace them. For foam air filters that are still in good condition, clean with dishwashing soap and hot water.

Clogged Fuel Filter

The fuel filter in your lawn mower prevents dirt and impurities from entering your mower’s fuel system. If you leave the filter in long enough, the accumulation of dirt will eventually prevent sufficient fuel from flowing into the fuel filter.

The solution is to replace the filter on your mower regularly. Stop the fuel supply before you replace the new fuel filter.

Insufficient Gas

Your Troy Bilt push mower won’t start if you have an empty tank or one with insufficient fuel. This simple fix is often easy to overlook at the moment. The fix is simply adding more fresh gas.

Make sure to use the correct type of gas. Your lawn mower won’t start if you use the wrong gas type or old fuel. The wrong gas type may damage your lawn mower. At the same time, using old gasoline will clog your mower or prevent it from running efficiently.

Tip: when storing your mower in the off-season, use a fuel stabilizer to prevent gas from spoiling during storage.

Plugged Gas Cap

 A plugged gas cap is another common reason a Troy Bilt mower won’t start. The gas cap (also known as a fuel cap) allows air to enter the fuel tank. This air keeps the fuel flowing into the carburetor, even when the gas levels decline.

When air doesn’t enter the fuel tank due to a clogged gas cap, a vacuum lock occurs inside the gas tank preventing fuel from flowing into the carburetor and engine.

If you are dealing with a plugged gas cap, clean it to remove debris and grime, then try to restart your mower. If that doesn’t work, try loosening your gas cap. If loosening the gas cap allows your mower to run, it’s time to replace the gas cap.

Damaged Spark Plug

A well-functioning spark plug ensures that the fuel-air mixture in your mower engine ignites. Constant use wears down the spark plug preventing enough charge from reaching the combustion chamber. In addition to regular wear and tear, dirt and debris on the spark plug can reduce its efficiency.

The easiest spark-plug fix is to clean it regularly. However, sometimes the best solution is to replace the spark plug entirely. A good rule is to replace your spark plugs at least once yearly or after 25 hours of use.

Tip: You can prevent most mower problems by checking your mower in the spring before you mow the lawn.

Defective Fuel Pump

You’ll find that your Troy Bilt mower can’t start if the engine does not receive sufficient fuel. A defective fuel pump is usually the culprit in these cases.

You may also notice fuel tank noises, a sputtering engine, surging power, or power loss. Replacing the fuel pump is the best fix in this case.

Clogged Fuel Line

If your lawn mower suddenly won’t start or is sluggish, it might be due to a clogged fuel line. Like most parts of your lawn mower, the fuel line is susceptible to clogging with debris and dirt from the environment or old fuel.

Start by checking where the clog is along the fuel line. You can use carburetor cleaner and compressed air to clear the blockage. If the blockage persists, replace the fuel line.

Final Thoughts

 A Troy Bilt mower won’t start for several reasons, some that you can fix instantly and others that need new parts. Some of these problems can be prevented by diligently maintaining your lawn mower during the off-season.

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