Why Your Cub Cadet Won’t Start (7 Reasons Plus Fixes)

Have you tried to start your cub cadet, but nothing happened? Perhaps this is the only time you have in your tight schedule to mow your lawn or remove snow from your driveway.

So, what could prevent a Cub Cadet from starting, and how should you fix it? There are several possible reasons why your cub cadet won’t start. You might be dealing with a dead or bad battery, clogged fuel filter, dirty carburetor, faulty ignition key, or bad gasoline.

Below are 7 reasons why a cub cadet will not start and how to fix each problem.

Clogged or Dirty Carburetor

Your cub cadet’s carburetor ensures the engine gets the right fuel to create combustion. After prolonged use, your carb might accumulate dirt. The dirt or clog usually results from using old gasoline that contains ethanol.

When your carburetor becomes dirty or clogged, it fails to regulate the amount of fuel the engine receives. As a result, the engine might run rough or fail to start.

How To Fix

  • Disconnect your cub cadet’s spark plug wire and ensure to ground it to your engine. Doing this will ensure the engine doesn’t start when working on it.
  • Remove the carburetor and use a carburetor cleaner to clean it. If you can clean the carburetor on your own, take it to your service technician for cleaning.
  • If the carburetor looks damaged, you may prefer to replace it. You can take your cub cadet to a technician to have the carburetor fixed or replaced.

Defective Ignition Switch

Your cub cadet will not start if you’re dealing with a faulty ignition switch. You can notice this problem after inserting the key and turning it, only to find nothing happens.

To determine if the ignition key is the culprit, use a multimeter to check continuity. Remember to insert the key and turn it when checking for continuity.

If your ignition switch is okay, its resistance will be near 0 (zero) ohms. On the other hand, a faulty ignition switch measures infinite resistance. If your ignition switch is defective, replace it.

Clogged Air Filter

The air filter in your cub cadet provides sufficient air to the engine, allowing the engine to run. With regular use, grass clippings, dust, and other materials can clog up the air filter, slowing airflow to the engine. When this happens, the engine consumes a lot of fuel and may overheat.

Your cub cadet won’t start if the air filter fails to supply the engine’s required air. If not fixed promptly, the engine will try to draw air from the crankcase, causing severe damage to the engine.

How To Unclog a Cub Cadet’s Filter

  • Remove the air filter from its housing and clean it with warm, soapy water.
  • Rinse the air filter thoroughly to avoid leaving any dirt.
  • Ensure the air filter is dry before reinstalling it back into its housing.
  • If the air filter won’t get clean or is damaged, replace it.

Bad or Loose Spark Plug

A spark plug provides a spark for igniting the air/fuel mixture in your cub cadet. If the spark plug has a loose connection or is damaged, it causes cub cadet starting problems. In most cases, a plug with oil or carbon buildup causes the engine to misfire and fail to start.

Your engine will also fail to start if there’s a loose spark plug wire or if the spark plug is incorrectly gapped.

How To Fix

  • Extract your spark plug and check whether it has signs of cracked porcelain. If you detect any damaged spark plug, replace it with a new one.
  • Clean the spark plug with a cleaner or a wire brush if it has signs of oil or carbon buildup.
  • Inspect the spark plug for loose connection. Follow the engine manufacturer’s specifications and use a feeler gauge to gap the spark plug correctly.

Old or Bad Gasoline

Your cub cadet won’t start due to old or bad gasoline. Gasoline deteriorates and loses its volatility in about 30 days. Over time, the old gas attracts moisture which evaporates, leaving a thicker, sticker residue behind. The sticky residue may clog the fuel lines, carburetor, and filter, resulting in cub cadet starting problems.

How To Remove Bad Gasoline From Your Cub Cadet

  • Use a fuel siphon pump to drain the old or bad gasoline from your cub cadet’s tank. Ensure to find a busy gas station where they store gasoline for a few days.
  • Add fresh, unleaded gas and utilize a fuel stabilizer to clean the fuel system. The fuel stabilizer will also be handy if your machine doesn’t consume gasoline within 30 days.

Bad Starter Solenoid

The starter solenoid sends an electrical current from your cub cadet’s battery to the starter. It actuates the machine’s starter motor when you’re turning on the engine. If the starter solenoid is faulty, it will prevent your Cub Cadet’s engine from starting.

The starter solenoid can go bad if:

  • There’s corrosion on the copper plate.
  • The spring becomes weak.
  • The battery is faulty.
  • The starter is weak.

You’ll know if your starter solenoid is faulty if you detect a hum or click when turning the ignition key.

How To Fix

  • Ensure the battery is fully charged before fixing any problem with the starter solenoid.
  • Check for any signs of damage on your starter solenoid. If damaged, replace it.
  • Ensure the connections at your starter solenoid are tight and clean.

Dead Battery or Corroded Terminals

If your cub cadet’s battery dies, it won’t provide the power to start the machine. You may also want to check for loose cables and corroded terminals. With regular use, the two cables on the battery might become loose due to constant vibration. Similarly, your battery terminals might corrode over time if you fail to conduct regular maintenance.

How To Fix

  • Use a voltmeter to check your battery voltage. If it’s below 12.0 volts, you’ll need to charge the battery. If the battery won’t hold a charge, replace it with a new one.
  • Access the battery cables and check if they’re loose. Connect them securely to the correct terminals.
  • If there’s corrosion on the terminals, clean them using baking soda, hot water, and Coca-Cola. Alternatively, you can buy a battery terminal cleaning spray.

Final Thoughts

A cub cadet won’t start due to a dead battery, old gasoline, bad starter solenoid, faulty ignition switch, loose spark plug, clogged air filter, and a dirty carburetor. Fortunately, you can troubleshoot most of these problems and bring your machine back to life. Consider taking your Cub Cadet to a service technician if you can’t fix the starting issue.