Starting a lawn mower that’s been hibernating for months can sometimes feel like wrestling with a stubborn beast. But fear not! With a little patience and the right know-how, you can coax that engine back to life and get your lawn looking its best. This comprehensive guide will walk you through the steps, potential problems, and helpful tips to ensure a successful start-up.
Preparing for the Resurrection: Initial Checks and Supplies
Before you even think about pulling the starter cord, a thorough inspection is crucial. This pre-flight check will not only increase your chances of a successful start but also help identify any potential issues that could lead to bigger problems down the road.
The Fuel Factor: Checking and Replacing Old Gasoline
Gasoline, especially when left sitting for extended periods, can degrade and become stale. This stale fuel can clog carburetor jets and prevent the engine from starting. The first step is to assess the fuel in the tank. If it smells pungent or looks discolored, it’s time for a change.
To drain the old fuel, locate the fuel shut-off valve (if your mower has one) and turn it off. Then, carefully disconnect the fuel line from the carburetor and drain the fuel into a suitable container. Dispose of the old fuel properly at a designated recycling center or hazardous waste collection site.
Once the old fuel is drained, add fresh, high-quality gasoline. Consider using fuel with a fuel stabilizer additive, especially if you plan to store the mower for extended periods again. This will help prevent the fuel from degrading.
Oil Check: The Lifeblood of Your Engine
Just like a car, your lawn mower needs clean oil to run smoothly. Check the oil level using the dipstick. Most mowers have markings indicating the minimum and maximum oil levels. If the oil is low, add the appropriate type of oil as specified in your owner’s manual.
Pay close attention to the condition of the oil. If it appears dark, gritty, or sludgy, it’s time for an oil change. Changing the oil is a relatively simple task that can significantly extend the life of your engine. Refer to your owner’s manual for specific instructions on how to change the oil in your mower.
Spark Plug Inspection: Igniting the Fire
The spark plug is responsible for igniting the fuel-air mixture in the engine. A faulty spark plug can prevent the engine from starting. Locate the spark plug (usually located on the side of the engine) and carefully remove it using a spark plug wrench.
Inspect the spark plug for any signs of damage, such as cracks, corrosion, or excessive carbon buildup. A dirty spark plug can often be cleaned using a wire brush. However, if the spark plug is severely damaged or worn, it’s best to replace it with a new one.
When reinstalling the spark plug, make sure it’s properly tightened to the manufacturer’s specifications. Overtightening can damage the spark plug or the engine.
Air Filter Assessment: Breathe Easy
The air filter prevents dirt and debris from entering the engine. A clogged air filter can restrict airflow and make it difficult for the engine to start. Locate the air filter housing and remove the air filter.
Inspect the air filter for dirt and debris. If the air filter is paper-based, try tapping it gently to dislodge any loose dirt. If it’s heavily soiled, replace it with a new one. Foam air filters can often be cleaned with soap and water, but be sure to let them dry completely before reinstalling them.
Blade Inspection: Sharp and Safe
While not directly related to starting the mower, it’s a good idea to inspect the blade before you begin mowing. A dull or damaged blade can tear the grass instead of cutting it cleanly, which can make your lawn more susceptible to disease.
Always disconnect the spark plug wire before inspecting or working on the blade. This will prevent the engine from accidentally starting. Check the blade for any signs of damage, such as cracks, bends, or excessive wear. If the blade is damaged, replace it with a new one.
If the blade is dull, you can sharpen it yourself using a file or take it to a professional sharpening service.
The Starting Sequence: Bringing Your Mower to Life
Now that you’ve thoroughly inspected your mower and addressed any potential issues, it’s time to attempt to start it. Follow these steps carefully:
Priming the Pump: Feeding the Engine
Most lawn mowers have a primer bulb that helps to prime the carburetor with fuel. Press the primer bulb several times (usually 3-5 times) to ensure that fuel is reaching the engine. Avoid over-priming, as this can flood the engine and make it difficult to start.
Setting the Throttle and Choke: Finding the Right Mixture
The throttle controls the engine speed, while the choke controls the air-fuel mixture. When starting a cold engine, you’ll typically need to set the choke to the “full choke” position. This enriches the fuel mixture, making it easier to start.
Once the engine starts, gradually move the choke to the “run” position. If the engine struggles to run smoothly, you may need to adjust the throttle to find the optimal speed.
Pulling the Cord: The Moment of Truth
Grip the starter cord handle firmly and pull it slowly until you feel resistance. Then, give it a sharp, steady pull. Avoid pulling the cord all the way out, as this can damage the recoil mechanism.
If the engine doesn’t start after a few pulls, repeat the priming and choke settings. You may also need to give the engine a few minutes to rest before attempting to start it again.
Electric Start Options: A Push-Button Solution
If your lawn mower has an electric start, make sure the battery is properly charged. Connect the battery charger according to the manufacturer’s instructions and allow it to charge fully. Once the battery is charged, simply turn the key or press the start button to start the engine.
Troubleshooting: When Things Don’t Go According to Plan
Sometimes, even with the best preparation, your lawn mower may refuse to start. Here are some common problems and potential solutions:
No Spark: Investigating the Ignition System
If the engine is turning over but not starting, the problem may be with the ignition system. Check the spark plug wire to make sure it’s securely connected to the spark plug. You can also use a spark plug tester to check if the spark plug is producing a spark.
If the spark plug is not producing a spark, the problem may be with the ignition coil. The ignition coil is responsible for generating the high voltage needed to create a spark. Testing the ignition coil requires specialized tools and knowledge. If you’re not comfortable working with electrical components, it’s best to take your mower to a qualified service technician.
Fuel Issues: A Carburetor Conundrum
If the engine is not getting fuel, the problem may be with the carburetor. The carburetor is responsible for mixing air and fuel in the correct proportions. A clogged carburetor can prevent fuel from reaching the engine.
Cleaning the carburetor can be a complex process that requires disassembling the carburetor and cleaning the jets and passages. If you’re not comfortable doing this yourself, it’s best to take your mower to a qualified service technician.
Compression Problems: A More Serious Issue
If the engine has low compression, it may be difficult or impossible to start. Compression is the measure of how tightly the air-fuel mixture is compressed in the cylinder. Low compression can be caused by worn piston rings, damaged valves, or a blown head gasket.
Checking compression requires specialized tools and knowledge. If you suspect that your engine has low compression, it’s best to take it to a qualified service technician.
Safety First: A Reminder
Working on lawn mowers can be dangerous if proper precautions are not taken. Always disconnect the spark plug wire before working on the engine or blade. Wear safety glasses to protect your eyes from flying debris. And never work on a lawn mower while it’s running.
Long-Term Storage: Preparing for the Next Nap
Proper storage is essential for ensuring that your lawn mower starts easily next season. Follow these steps to prepare your mower for long-term storage:
- Drain the fuel tank completely.
- Change the oil.
- Remove and clean the spark plug.
- Clean the air filter.
- Sharpen or replace the blade.
- Store the mower in a clean, dry place.
- Consider using a fuel stabilizer in the last tank of gas before storage.
By following these tips, you can ensure that your lawn mower is ready to go when you need it next season. Starting a lawn mower after it’s been sitting doesn’t have to be a daunting task. With a little preparation and patience, you can get your mower running smoothly and keep your lawn looking its best. Remember to always consult your owner’s manual for specific instructions and safety precautions.
Why won’t my lawn mower start after sitting for a long time?
The most common culprit for a lawn mower refusing to start after a period of inactivity is stale fuel. Gasoline degrades over time, leading to a gummy residue that can clog the carburetor and fuel lines. This residue prevents the proper mixture of air and fuel needed for combustion, effectively starving the engine.
Other potential reasons include a dead or weak battery (especially in electric start models), a clogged air filter restricting airflow, a fouled spark plug hindering ignition, or even rodent activity damaging wiring or fuel lines. A thorough inspection of these components is crucial for diagnosing the problem and implementing the correct solution.
How long can gasoline sit in a lawn mower before it goes bad?
Generally, gasoline starts to degrade noticeably after about 30 days, especially if it’s not treated with a fuel stabilizer. Factors like temperature fluctuations and exposure to air accelerate this process. The degradation leads to the formation of gums and varnishes that can clog small engine components.
For optimal engine performance and longevity, it’s best to drain the fuel tank and run the engine dry before storing the lawn mower for extended periods (like over the winter). Alternatively, use a fuel stabilizer according to the manufacturer’s instructions. Fuel stabilizer can extend the life of gasoline to approximately 6-12 months, preventing the formation of harmful deposits.
What is fuel stabilizer and how do I use it?
Fuel stabilizer is an additive designed to prevent gasoline from degrading over time. It works by inhibiting oxidation and preventing the formation of gums and varnishes that can clog the fuel system. This helps maintain the octane level of the fuel and ensures it remains combustible.
To use fuel stabilizer, simply add the recommended amount (as per the product’s instructions) to your gasoline can or directly into the lawn mower’s fuel tank. For best results, add it to fresh gasoline. Run the engine for a few minutes to circulate the treated fuel throughout the fuel system before storing the lawn mower.
How do I drain the old fuel from my lawn mower?
Before draining fuel, ensure the engine is cool and you’re working in a well-ventilated area away from any open flames or sparks. Disconnect the spark plug wire for safety. Most lawn mowers have a drain plug on the carburetor bowl. Place a suitable container underneath to catch the fuel.
Carefully loosen the drain plug to allow the fuel to flow out. If your mower doesn’t have a drain plug, you can siphon the fuel out using a siphon pump or carefully tilt the mower over a container, ensuring you don’t spill fuel onto the engine or surrounding areas. Dispose of the old fuel properly according to local regulations.
How do I clean a clogged carburetor on my lawn mower?
Cleaning a carburetor requires some mechanical skill. Begin by disconnecting the spark plug wire. Then, carefully remove the air filter and any surrounding components that obstruct access to the carburetor. Take pictures during disassembly to aid in reassembly.
Next, detach the fuel lines and remove the carburetor. Disassemble the carburetor carefully, noting the position of all jets and screws. Clean each component thoroughly with carburetor cleaner and small brushes. Reassemble the carburetor, ensuring all parts are correctly positioned and tightened. Reinstall the carburetor and reassemble all the components you removed.
What if my lawn mower still won’t start after cleaning the carburetor?
If the lawn mower still refuses to start after cleaning the carburetor, double-check that the spark plug is clean and properly gapped. A fouled spark plug can prevent ignition. Use a spark plug cleaner or replace the spark plug if it appears heavily soiled or damaged.
Also, verify that the air filter is clean and allows adequate airflow. A restricted air filter can disrupt the air-fuel mixture. Inspect the fuel lines for any cracks or leaks and replace them if necessary. If the problem persists, it might indicate a more serious issue, such as a faulty ignition coil or low compression, which may require professional attention.
How often should I service my lawn mower?
Regular servicing is crucial for maintaining the performance and extending the lifespan of your lawn mower. At a minimum, you should change the oil, clean or replace the air filter, and sharpen or replace the blade annually. Refer to your owner’s manual for specific maintenance recommendations.
In addition to annual servicing, it’s good practice to inspect the lawn mower before each use. Check the oil level, ensure the blade is sharp and balanced, and clean any debris from the engine and deck. Proper maintenance prevents issues from arising and ensures your lawn mower starts reliably every time.