How To Fix A Lawnmower: 5 Common Problems

Repair your lawnmower at home with STABIL and these 5 small engine repair tips. Lawnmower won’t start? While some lawnmower problems are preventable, others are inevitable.

It is important to learn how the mower works and how to fix a lawnmower at home. Always consult the owner’s manual for any mower before attempting repairs at home. If the mower is under warranty, consult the manufacturer before trying to figure out how to fix a lawnmower at home.

5 Common Problems And Lawnmower Troubleshooting Tips

Fortunately, it is easy to learn small engine repair and basic lawnmower repair when it comes to simple issues. Most problems can be remedied with a few tools, replacement lawnmower parts, and patience. To save money, always use these lawn mower repair tips for fixing a lawnmower at home before running out to buy a new mower.

1. The Starter Rope Is Stuck Or Is Hard To Pull

This problem is usually caused by the engagement of the engine flywheel brake. Check to see if the flywheel brake is pressing against the handle before pulling the rope again. When the flywheel brake is not the issue and the problem persists, check the lawnmower blade.

A rope that is stuck or hard to pull may be caused by the blade dragging on the ground or by clippings getting stuck to the blade. To address this issue, place the mower on a hard surface. Make sure the engine is shut off and the spark plug wire is not engaged. Carefully clean the bottom side of the blade to remove any clippings or dirt, put the mower back into position and try pulling the cord again. If the problem persists, one or more lawnmower parts may not be functioning correctly and will need to be repaired. Consult the owner’s manual or search online for repair guides for the specific model and brand of mower.

2. The Lawnmower Loses Power While Moving

At some point in time, nearly every lawnmower owner will be pushing the mower along and suddenly hear it sputter as the engine stops.

  • One of the most common causes is a dirty filter. Use the owner’s manual to determine where the filter is. Remove the filter and clean it. If the filter is very dirty it may need to be replaced. This is one of the most inexpensive lawnmower parts to replace.
  • If the filter is not the issue, compare the height of the grass to the mower’s cutting height setting. If the grass is tall, adjust the cutting height accordingly.
  • Another way to fix lawn mower power issues is to clean the blade. Refer to the owner’s manual and use the manufacturers instructions to clean the mower blade.
  • If this does not fix the issue, check the spark plug. Many people are able to quickly repair their lawn mowers by cleaning or replacing a spark plug. Spark plugs are also affordable mower parts that are sold online or in home improvement stores.

3. The Lawnmower Starts Smoking

Prevent lawnmore repairs. Be sure to use STABIL 360 Performance Small Engine Fuel Stabilizer regularly. This is one of the most startling issues to encounter – most people assume that the engine is about to die or blow up. However, this problem is usually not very serious. The engine often smokes when the chamber that holds oil is too full. Check the chamber to see if this is the issue. Another problem may be a leak in the oil chamber. If the mower leans to one side while mowing on a slope, the oil may leak out onto the muffler and cause the smoking. When the mower’s engine is off and has cooled, inspect the oil chamber area for leaks. The issue may be that the cap is not on tight enough. If the part must be replaced, it may be easier to look for the part online than to search for it in stores.

In rarer cases, the smoke may be a sign of a serious issue. If the smoke is white or very light in color and the mower does not run continuously, it is time to have a professional repair company look at the mower.

4. The Lawnmower Will Not Start

The first step in learning to repair lawn mower starting issues is to check the gas tank. An empty gas tank is the most common cause of a lawnmower not starting. Mower owners who are diligent about keeping their tanks full should still check the tank to see if there is a leak. If the tank is empty but should not be, inspect the outside of the tank for leaks. Replacement tanks can be found using an online lawnmower parts site.

Remember, in order to keep your fuel fresh if you’re going to be storing your lawnmower, use STA-BIL® Storage. It will keep your fuel fresh for 12 months and help protect the fuel tank from the effects of ethanol gas. Also, if there is a shut off valve for the gas lines, by all means, use it.Using STABIL Products for outdoor power equipment helps prevent small engine and lawnmower repairs in the spring and summer.

If the gas tank is not the issue because the mower runs on a battery, check the battery for signs of damage. Lawnmower batteries may also lose their ability to hold a charge as they age. Look for replacement lawnmower batteries if the battery needs to be replaced. Lawnmower batteries vary in price depending on the brand and model of mower.

Another important step in learning how to fix a lawnmower that will not start is checking the spark plugs. If they are dirty, clean them thoroughly. Reconnect them if they are loose. Old spark plugs should be replaced with new ones. If the fuel is not getting to the engine, knock on the carburetor’s side to help the gas flow again. If this does not fix lawn mower issues of this nature, look for a new fuel filter online.

5. The Lawnmower Loses Speed

When a lawnmower slows down considerably, the issue is usually a dislocated or damaged drive belt. This part is located in the motor casing. Consult the owner’s manual to verify the location. With the mower turned off, inspect the drive belt. If the belt is loose but not damaged, reattach it. If it is damaged, replacement belts are usually easy to find online from a lawnmower parts site. A new belt should repair lawn mower issues of this type. If the lawnmower runs on batteries, check the battery. Some lawnmower batteries may cause this issue if they malfunction, however, it is not common for lawnmower batteries to slow a mower’s speed.

How To Prevent Lawnmower Problems

Knowing how to repair a lawnmower at home saves time and money. The easiest way to avoid frequent problems is to maintain the mower. Follow these simple tips to keep the mower in good condition:

– Always use the correct type of replacement lawnmower parts.
– Clean the blade regularly. Make sure to pull the plug so there is no chance that the blades can move while you’re cleaning them.
– Oil any moving parts when needed according to the manufacturer’s instructions.
– Change the oil as recommended.
– Use the correct type of fuel.
– Recharge lawnmower batteries according to instructions but avoid overcharging them.
– Store the mower in a cool, dry and covered space when it is not in use.
– Have the mower serviced as recommended by the manufacturer or warranty.

Leave a Reply

  • lawnmower sputters when level with ground.If deck is raised by pushing down on lawnmower handle motor regains speed.what could be possible solution to this problem.has full tank of gas.

    • There are many reasons as to why this may be happening. From trying to cut grass that may be too tall to mechanical failure. Before taking it to a mechanic, I would recommend inspecting the blade, filter, making sure that belt is the right size or in good shape, check the safety switch (if any), and see if there is any damage that may be visible.

      • I’m having the same problem as Robert Glenn. 21″ Briggs & Stratton cheapo Lowes special! I have replaced the spark plug and changed the oil just now, and the filter is beautiful at what I would estimate to be 5% dirty and 95% clean. Gave that a good brushing.

        So I just now spent $10 for a new plug and oil on a lawn mower that originally cost $99 and this still doens’t solve the problem. I’m at the point where I should just buy a new mower every year and it would probably save me time & hassle rather than spending a couple hours trying to troubleshoot and guess at parts to replace.

        It’s the weirdest thing: the mower runs fantastically well when NOT level, but when I try to make the mower level it stutters and shuts off. WHAT in the world would cause THAT?

  • My Craftsman mower Model# is 917.371940.
    When starting, it will spew dark blue smoke from the left lower side of the motor, vibrating the motor and for a few seconds and dies.

  • I use Sta-bil in everything!

  • can having the wrong drive belt on affect the brakes?

    • Hello Pete, we suggest referring this question to a trusted professional mechanic since we are unable to assess the situation in-person.

  • lawn mower won’t move when first started everything
    works except when I put in drive it has to warm up before it will move hydro stat drive may need oil where do I add oil

    • Hi Howard, since we are not able to assess your mower in person we suggest taking it to a trusted mechanic. Thank you.

  • I have an antique edger powered by a single cylinder four stroke. It uses a grounding strap or tab to shut off the engine. I got shocked badly by one of these when I was kid and I don’t want to get “bit” again. How do you properly use a grounding tab or strap to stop an engine?

    • Hello Jim! In this particular situation, perhaps it would be helpful seeking a second opinion from a different professional technician. If you have any other questions please contact consumer support at

  • my mower runs fine for 20 or 30 minutes then it dies and I have to let it cool down and then it will start and run again. what could be causing this?

    • Hello! Thank you for the question. However, in this particular situation, perhaps it would be helpful seeking a second opinion from a different professional technician. If you have any other questions please contact consumer support at

  • The self propelled drive does not work.

  • I’ve got a lawn mower that does not start. When I pull the cord it doesn’t even cough. If I leave it out in the sun with the carburetor facing the sun and let it sit for an hour or so it usually starts. It has to be a hot sunny day though. I’ve used Start Your Engines and that usually works. It worked better with the bottle instead of the new aerosol can. Any ideas for a fix?

    • Hi, Rich! If this is a constant problem, we recommend to consider changing fuel sources to rule out the possibility of “bad gas”. Also, adding STA-BIL 360 Performance to the fuel would help in preventing condensation and oxidation issues. If the problem continues, perhaps giving the mower a good maintenance checkup would help. If you have any other questions please contact consumer support at

  • I have a craftsman riding mower it won’t start when I turn the switch they said it the brake switch if that doesn’t do it then it’s the seat switch wrong it still has nothing on the switch but you can jump the solenoid starts right up any idea s?

    • Hi, John. In this particular situation, perhaps it would be helpful seeking a second opinion from a different professional technician. If you have any other questions please contact consumer support at

  • I ran over a rope that got tangled in the blades and after i untangled it the lawnmower wont start now

    • Hello, we recommend to consult with a professional for this situation. If you have any other questions please contact consumer support at

    • check the flywheel positioning key as is made to shear when the engine suddenly stops, this is to prevent further serious damage being caused to the engine, if this key is sheared the engine will nor start as the ignition timing is then wrong.

  • My lawn more stalls after using it for a short period of time and I am unable to start it back up. History short period of time and lawnmower starts up again they could use it for another five minutes I got gas at the well there’s nothing court in the blade. Could be the spark plug

  • Thanks for the great mower repair tips. Our lawn mower has been acting weird recently, and isn’t really cutting. I didn’t realize that the filter could be the reason it’s stopping. I’ll have to look for a new filter to buy so that I can replace that.

  • i have a42′ aries riding lawn mower when i try to start it the starter is making a clicking sound and it will not start back up can you help me with this problem

  • I have a craftsman gt 5000 garden tractor. I have replaced the seat safety switch and the clutch interlock switch. When I let off the brake/clutch the engine dies. Whats the next step in troubleshooting?

  • Tractor mower looses power won’t go forward or backward

  • my husquarna mower starts up on the first pull. getting it to shut off is the problem. Moving the throttle to off only slows it down Have to pull plug wire to shut down

  • Lawnmower is surging or hunting

  • My toro 20332 is stalling when I go uphill and I hear a grinding sound. Ive changed the drive wheel(back left wheel)and the drive belt. If I stop trying to go forward the engine acts normally. Any ideas. Thanks

    • Hi, Wayne. Perhaps in this situation it would be best to consult with a professional. If you have any other questions please contact our Consumer Support Team at

  • I di not find my problem answered here. I was told the lawn mower may have got water in the gas tank. I did some repairs on carburetor and cleaned the lines, but when I pull the starter rope the engine turns over and then seems to lock up until I pull the rope again. Why would it do that even when I remove the spark plug? And what can I do to fix it?

    • Hi, Hugh. Perhaps in this situation it may be best to consult with a professional. If you have any other questions please contact our Consumer Support Team at

  • I was using my Troy Built self-propelled lawn mower and it died after only making one pass over the yard. I thought maybe it had gotten clogged by the grass being taller. When i tried to recrank it, the pull cord is almost impossible to pull and the self propelled lever is floppy, for lack of better word. any ideas?

    • Hi, Ashely. It is difficult to diagnose the issue without physically inspecting the mower. If any of these tips do not work, perhaps consulting a small engine mechanic may be the best option. Thanks for stopping by!

  • I have a John Deere X300 w/ Kawasaki Engine. When using the key switch, the lights come on, but the engine will not turn over. I replaced the Starter Solenoid, but that wasn’t it. I can jump the main terminals on the solenoid and it’ll start. The seat switch, brake switch and mower deck switch are functioning properly. Any ideas as to where I need to go from here?

    • Hi, Buddy. It is difficult to diagnose the issue without physically inspecting the mower. If any of these tips do not work, perhaps consulting a small engine mechanic may be the best option. Thanks for stopping by!

  • I liked that you said that one way to prevent the need for major repairs on your lawnmower is to make sure that the blade and other important parts are cleaned and handled carefully. I have been thinking about buying a lawn mower but I have been worried about the need for major repair and that this would become expensive. I would be sure to perform proper routine cleaning and maintenance in order to avoid this issue.

  • I have a 10 year old Briggs and Stratton. The housing bolts keep popping out what can I do to fix?

  • My lawnmower is start smoking white smoke at start and later smoke start turning black. Why?

  • Lawn mower stops working when it gets hot

  • My Honda engine on a Craftsman lawn mower kicks back when I attempt to start it with the rope start. Darn near pulls my
    arm off (not really but it does rip the cord out of my hand) What could be the problem?.

  • What cause a riding mower to stall when the brake pedal is released