My Lawn Mower Slowly Loses Power and Then Dies

You are just mowing along as usual and your lawn mower will slowly lose power and then it will just shut off. This is not an instant shut down, it happens over a minute or so.

In many cases this is a simple fix and to test what the problem is, loosen the gas cap a little and if you hear air rushing in as you do, it probably means that your gas cap is not venting properly. A gas cap is supposed to let air into the gas tank but not let it escape.

Now start your lawn mower and see if it runs for a long time. If it does, you have a bad gas cap. If you still have the same problem, you need to check your fuel filter and down the line to the carburetor. Check the fuel filter by pinching off the fuel line and removing it from the carburetor. Then release the pinched hose and let it drain into a clear glass container. If the fuel doesn’t come out of the hose with any quantity, you most likely found the problem. If the flow is good, move onto the carburetor. It will need to be taken apart and cleaned of any debris or ethanol intrusion.

Still need help with your lawn mower? Visit our Locations page for a lawn mower repair shop near you.

What Does a Riding Lawn Mower Tune-up Consist Of?

So your lawn mower needs a tune-up and you are wonder what they actually should do during that preventive maintenance.

Here is a checklist that I use to ensure my clients get their riding lawn mower serviced properly.

If you need a riding lawn mower shop in your area, check out our Locations page for a shop near you.

Riding Lawn Mower Tune-Up Checklist

  • Document Model Code and Serial Number – Look For Service Bulletins
  • Clean Mower With Leaf Blower Under Hood, Deck, Chassis & Transmission
  • Start Engine – Warm Up – Check Spark – Check All Functions of Mower & Test Drive
  • Test Safety Switches – Brake Test
  • Test Charging System While Running & Battery After Shutdown
  • Change Oil and Filter
  • Check Compression L______R______
  • Remove Hood & Put Rider on Lift
  • Change Air Filter, Fuel Filter & Spark Plugs
  • Clean and Coat Battery Terminals
  • Remove Blower Cover and Clean & Degrease Engine
  • Clean Carburetor if Necessary
  • Inspect Engine for Damage, Wear or Missing Parts
  • Grease Fittings in Steering, Wheels, Axles, Chassis & Deck Spindles
  • Check Front Wheel Bearings & Steering Support Inserts
  • Inspect Electrical, Mechanical and Control Cable Systems
  • Inspect Fuel and Vapor Lines to Tank & Gas Cap
  • Inspect Deck and Drive Belts – Brake Pad
  • Inspect Drive Spindles for Binding or Bearing Wear
  • Inspect Deck Pulley’s and System Parts
  • Lubricate Mechanical Linkages & Control Cables with Dry Lube
  • Remove Blades and Sharpen – Scrape Deck – Install Blades -Torque to Specs
  • Inspect Transmission Oil Level & Cooling Fan ÿ Transmission Mount Brackets
  • Fill Tires With Air – Normally 18psi Front and 10psi Rear
  • Check Tires for Wear & Damage – Check Scalp Wheels for Wear & Damage
  • Level Deck if Necessary


Lawn Mower Engine Sputters

What is causing that aggravating sputtering sound from your lawn mower? Well, it depends on what kind of sound it is. If it is an intermittent sound and the lawn mower is losing power, you may very well have water in your gasoline.

Water in gas is a big problem today because of the ethanol that is added to it. Ethanol is essentially alcohol and alcohol attracts moisture from the air through an open vent cap or unsealed gas can.

When the engine is running, it will try to burn this water and will begin to sputter and especially under higher loads such as thicker grass. The sputtering may clear up or it may get worse. Alcohol is heavier than gasoline so it tends to sink to the bottom of the gas tank and the carburetor bowl. As the mower is cruising along, the water and gas will splash around and you may get some water sucked up into the carburetor or it may be a splash of gas.

What I like to do in this case is to shutoff the fuel and then pull the fuel line off the carburetor and get a fuel sample with a clear glass jar. If there is water in the gas tank, there will be water in the fuel system and that will need to be cleaned out.

If you need a lawn mower repair shop in your area, visit our Locations page.

Lawn Mower Leaks Oil From Crankcase

Occasionally we see an oil leak from the crankcase gasket that seals the two halves of the crankcase together. Or a pinhole develops in the actual casting of the crankcase and oil will seep out of it. Other areas that leak are protrusions through the crankcase such as the governor arm shaft. Head gaskets can be another source of an oil leak out of the crankcase. An oil seal at the crankshaft is another oil leak source.

Note: Be extra cautious during the testing as you are working near a lawn mower blade. You can shutdown the engine prior to checking for where the engine is leaking for safety.

There are some dyes that can be added to the oil to find a hard to find oil leak. You put the dye in the crankcase and run the engine to get it warmed up. Then a black light is used to identify where the oil leak is coming from.

If you don’t have access to this type of testing paraphernalia, thoroughly clean the engine crankcases and then run the engine until it is warm. Look over the areas that you suspect the leak is coming from and look for the slightest weeping of oil. Wipe the area down and continue to monitor it.  Some leaks are difficult to find, but you will eventually find them.

Why a Honda Lawn Mower is Better Mower?

When you buy practically anything with the Honda name on it, you are getting a quality product. Whether it is a lawn mower or a car, Honda just puts the engineering and the quality into everything they make. Yes, you are going to pay a little more for Honda products, but as the old saying goes “You get what you pay for” still rings true.

The Honda lawn mower engine is very dependable and with routine care, it will last for a long time. Parts are readily available for new and older Honda mowers, so you can keep them going long after that other brand wears out.

The drivetrain is built solid to take a beating. Sometimes drive axles can be a problem with freezing up, but this is a problem that can be resolved without much expense.

The decks are made of good steel and are not thinly made. If they are kept free of wet grass, they will last a long time.

The controls are fairly easy to navigate and are user friendly. Some are quite different than what you are used to on a self-propelled lawn mower, but you get used to them pretty quickly.

I am a Small Engine Mechanic by trade and if I were to need another lawn mower, it would certainly be a Honda.

Lawn Mower Engine Surges up and Down

Do you ever wonder why your lawn mower engine revs up and down? The annoying sound that also affects the power your lawn mower puts out is caused by a fuel delivery or vacuum leak issue.

The engine gets enough fuel and then it doesn’t and so on and so forth. After a while the mower will develop a more serious engine problem and may begin to hard start or not even start at all. The surging could also become worse and the swings between high and low will get longer in duration.

This is a problem that is best suited for a lawn mower engine specialist to check out. Our Locations page has a listing of lawn mower repair shops in your area to help resolve this problem for you.

You can check the easy things such as slightly cracking the gas cap to see if the surging stops or change or clean the fuel filter if it has one. Some fuel filters are in the tank and not easy to see. You may have to drain the tank and then flush it out.

The other items are the carburetor and gaskets. Fuel lines can be the culprit too. Systematically check these items for blockage and air leaks to find the cause of the problem.

Push Lawn Mower Blade Hitting Deck and Making Noise

Occasionally you will hit something hard enough to bend the deck or the blade. With such thin metal decks today, they are easily bent. If your deck is rusting, parts can come loose and hit the blade as well. Some decks have guards inside of them that are spot welded together and when those welds come loose, the guard will hit the mower blade and you will hear quite the racket!

To inspect this area, pull the spark plug boot off the spark plug and then raise the mower deck from the front. It is not a good idea to lean the mower over side to side as this can cause the oil to leak out of the carburetor through the air cleaner.

Look for anything that is loose or for the blade that is bent. Slowly rotate the blade to see if it hits anything and you will likely find the cause of this problem pretty quick. Either the blade will need to be replaced or the deck metal repaired. You should also check to see if the crankshaft is bent while you are slowly turning the blade as this can cause the problem as well.

If you need a lawn mower repair shop to check out this problem for you, visit our Locations page for help finding a small engine shop in your area.

My Lawn Mower is Leaking Gas From the Carburetor

If the gas is leaking directly from the throat of the carburetor, that can be a sign of a needle and seat not properly sealing. Over time, contaminants will build up on those components and cause them to leak. A complete carburetor overhaul is usually the cure for this problem.

If gas is leaking from another part of the carburetor such as the float bowl, it could be a loose bowl nut or a bad gasket on that nut. The O-ring that seals the bowl to the carburetor could also be bad. Replace these parts and be careful to clean the grooves that hold the O-ring in place as buildup of dried fuel can cause that to leak as well.

If fuel is leaking from another part of the carburetor such as a jet screw,  it is time to replace the carb with a new one. Make sure to order new gaskets when you replace the carburetor to ensure there will not be any air leaks. An air leak will cause the lawn mower engine to surge and run lean. This means it has more air than fuel.

Fuel leaks can be dangerous and lead to an engine fire. Take them seriously and if you need a lawn mower repair shop to assist with your problem, visit our Locations page for help.

My Riding Lawn Mower Cuts Unevenly

Uneven can be a vague term when talking about how your riding lawn mower cuts. Does it scalp the lawn when you turn or cut lower on one side than the other?

Those are two of the most common problems and a third is that the front of the deck cuts more than it should.

Put your riding lawn mower on a flat concrete or gravel surface and visually inspect the deck. Does it lean to the left or right? Is it low in the front and high in the back? Once you determine what the problem is, you can now make adjustments. A tape measure works to adjust the deck from side to side and get it as level as possible. There is a special tool designed for this that measures the height at the blade tips that is available on Amazon or other retailers.

The deck must also be adjusted so the height in the front and rear are correct. A general rule is that there only be 3/4″ difference from front to rear in height. So adjust that accordingly to get the height right.

Are your scalp wheels missing or wearing out? This can cause the deck to scalp the lawn when you make turns. Replace them and the bolts and nuts if they are out of specifications.

These small adjustments can make a world of difference in the look of your yard after you mow, so make them and go test the mower to see if it resolved the problem.


My Riding Lawn Mower Pulls To One Side

It is pretty annoying when your riding lawn mower does not track straight. It either pulls to the left or pulls to the right and never seems to go where you want it to without a fight.

The good news is that this is a solvable problem and I will give you some things to check to correct this problem and get your lawn mower back on track.

The easy thing to check is your tire pressures. A low tire on either side will cause the mower to pull in that direction. So a tire that is going flat on the right side will cause the mower to pull to the right side and you need to keep putting left correction into the steering wheel to keep the mower going straight.

So check all the tire pressures. The front tires are normally around 15psi and the rears are at 10.

Raise the front end up and check axles and bearings. They should feel tight and not have a lot of play in them when you move them back and forth. If they are loose, replace them with new bearings and check that the axles are not damaged with grooves worn in them.

There is a tie rod that can be adjusted as well on one or both wheels. Look at the mower from the front and see which wheel is pointed in or out. Sometimes they are both pointed in the wrong direction and an adjustment will cure this problem. If your tie rods are non-adjustable, they will need to be replaced.

Lastly, check the steering gear to be sure that it is not worn out or slipping in the gears. These gears need lubricated during maintenance to prevent them from wearing out.

These are the most common problems that cause steering issues. Check them one at a time to solve your steering problem in your riding lawn mower.

If you need professional help with your riding lawn mower, visit our Locations page for a shop near you.