You purchased a walk-behind push or self-propelled lawn mower to keep the outdoor appearance of your home looking its best.
Just like with any brand mower, when you own a PowerSmart mower long enough, you are likely to run into problems including a failure to start.
A PowerSmart lawn mower won’t start when the engine isn’t getting sufficient air, fuel, and spark.
This can be caused by old fuel, lack of fuel, a clogged fuel line, a plugged fuel strainer, a dirty carburetor, a plugged air filter, a bad fuel cap, a bad spark plug, a faulty ignition coil, or a bad recoil.
Before performing any repairs on a PowerSmart Mower, follow all safety procedures outlined in your operator’s manual. This includes removing the spark plug wire.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
Reasons Your PowerSmart Lawn Mower Won’t Start
Empty Fuel Tank
Your PowerSmart mower has a small fuel tank on it. You may have forgotten to check the fuel level before you start mowing and now you ran out. Don’t forget to check this simple issue to a starting problem.
It’s easy to forget to check the fuel level when you’re frustrated.
If you find you are low on fuel, fill your 4-stage PowerSmart with fresh gas. Make sure you choose gas with a minimum octane rating of 87 and a maximum ethanol content of 10%.
Bad or Old Fuel
It’s not good to let fuel sit in your PowerSmart for long periods and not consume it. Fuel can begin to break down and lose its combustible properties as soon as 30 days after purchase.
Much of today’s fuel contains ethanol, an alternative plant-based fuel, to make fuel more environmentally friendly. While fuels with ethanol are okay to run in most vehicles, it’s not good for the small engine on a PowerSmart.
Ethanol attracts moisture to the fuel system. This water and ethanol mixture will leave behind varnish and gummy deposits when left sitting in your mower for long periods. This will cause fuel restrictions and fuel component failure.
Because of the negative effects ethanol has on a PowerSmart mower, it’s important to keep these things in mind when purchasing, storing, or consuming fuel:
- Purchase fresh fuel with a minimum 87 octane rating.
- Never use gas with more than a 10% ethanol content. Ethanol-free fuel is best.
- Consume fuel within 30 days.
- Use a fuel stabilizer if you are unable to consume it within 30 days to make it last a little longer without breaking down. (Fuel stabilizer must be added to fresh fuel. It will not reverse the effects of old fuel).
- Store fuel in an approved fuel container away from moisture or combustible products.
If you find old fuel in your PowerSmart mower, drain the fuel using a fuel siphon pump. Mix fresh gas with a fuel additive to help clean the fuel system, reduce moisture, and stabilize the gas.
I like a product called Sea Foam Motor Treatment. I use this product in every tank of gas to help reduce the issues that can result from using fuel with ethanol.
You can read more about this product in “Use Sea Foam Fuel Additive in a Lawn Mower to Stabilize Your Fuel“.
Bad Fuel Cap
The fuel tank on your PowerSmart must vent to equalize air pressure. When it is unable to vent, a vacuum is formed that keeps fuel from flowing out of the tank. Your mower won’t start when it isn’t able to get fuel.
The fuel cap allows the fuel tank to vent by allowing air to pass through the cap. The fuel cap can fail when it is broken or becomes plugged.
To determine whether your cap is the cause of your starting problem, loosen or remove your cap to allow air inside the tank and then attempt to start the mower.
If it starts, but stops running again after you place the cap back on the mower and allow it to run for a while, you may have a problem with the cap. You should replace a bad fuel cap.
Blocked Fuel Line
The gummy deposits or dirt left behind by old fuel can clog the fuel system including the fuel line. Check for clogs in the fuel line that could be restricting fuel to the engine.
To do this, shut off the fuel supply using the fuel shut-off valve (if your mower uses one) or crimp the fuel line to stop fuel flow using a pair of fuel hose pinch-off pliers.
With the fuel shut off, remove the end of the fuel line attached to the carburetor.
Place the line in a container. The container must be placed lower than the fuel tank so fuel can use gravity to flow. This is because fuel can’t run uphill without the assistance of a pump.
With the fuel line in the container, turn on the fuel supply and watch it flow into the container. If you are getting a good flow of fuel, the problem is not in the fuel line. Stop the fuel flow and reattach the line.
If you aren’t getting good flow, with the fuel flow off, remove the fuel line from the lawn mower. If you don’t have a fuel shut-off valve, your only option may be to drain the fuel tank to stop the flow before removing the line.
Once the line is removed from the mower, spray carburetor cleaner into the line to loosen the clog. Blow compressed air into it to remove the clog. Repeat using carburetor cleaner and compressed air until the line is free of any clogs.
Reinstall the fuel line once you have removed the restriction. Purchase a new fuel line if you can’t remove the clog or if the line is damaged or cracking due to age.
If you find the problem wasn’t in the fuel line, proceed with checking the fuel strainer.
Plugged Fuel Strainer
If you have a fuel restriction before fuel gets to the carburetor and your fuel line is okay, it’s time to check the fuel strainer. This is a small part attached to the fuel tank to strain fuel before it enters the fuel line.
This is to prevent dirt and other debris from getting into the fuel system and wearing on the fuel components and engine.
With the fuel tank drained, remove the fuel strainer and inspect for clogging. Clean the screen to remove dirt or replace it with a new one if needed.
The carburetor’s function is to regulate the amount of gas mixed with air to form combustion in the cylinder.
When the carburetor is dirty and gums up from old fuel, components in the carburetor no longer function properly. The carburetor may not allow the gas required to start your PowerSmart mower.
If you have verified you are getting fuel to the carburetor, remove the air filter and spray carburetor cleaner into the air intake. Start your mower. If it starts, runs, and then shuts down, take your carburetor apart to clean it.
Plugged Air Filter
A plugged air filter can restrict airflow to the mower and not allow the engine to get the air it needs to form combustion. It is best practice to replace your air filter annually.
You must also check and clean the filter regularly throughout the mowing season.
To clean a paper air filter, remove the filter from the air filter housing. Wipe out loose dirt from the housing. Do not allow dirt to fall into the air intake.
Tap the filter against your hand to knock the dirt off the filter. If it is very dirty, damaged, or wet, replace it with a new air filter.
Some air filters on a PowerSmart mower also have a foam pre-filter that fits around the paper air filter. This is to help collect dirt before it gets to the paper primary filter.
To clean a foam pre-filter, wash it in a solution of warm water and mild detergent. Rinse until the filter runs clear.
Allow it to dry completely before placing it around the paper filter element. If the foam pre-filter is torn or worn, you should replace it with a new one.
Bad or Improperly Gapped Spark Plug
A spark plug can be faulty when the tip is dirty, the porcelain is cracked or the electrode is burnt. This will cause your mower not to start.
You can clean the spark plug to remove the deposits. If your spark plug is very dark in color or damaged, you must replace your spark plug.
Your spark plug needs to be properly gapped following the manufacturer’s specifications as found in the operator’s manual. Starting problems can be caused by a spark plug that is gapped incorrectly or loose spark plug wires.
Bad Ignition Coil
Before checking for a bad ignition coil, make sure your spark plug is in good condition. The ignition coil provides voltage to the spark plug so it can start the engine.
If the spark plug isn’t able to fire, the engine will not start. Check the continuity of the ignition coil using an ohm meter. If you find a break in the continuity, replace the ignition coil.
The recoil on your mower may no longer be able to start your mower. A rope on the recoil can become unstrung or you may find you have a broken pulley, springs, or clips in your recoil that need to be repaired.
Sometimes, restringing the recoil is all you need. Other times you will have to replace broken parts in your recoil. Before doing this, price out a full recoil replacement.
Depending on the price difference, it may be better to replace the recoil assembly over tearing it down and replacing broken components.