Category: Lawn Mower Repair Tips

Lawn Mower Repair Tips

How To Find a Good Small Engine Repair Shop

Looking for a good small engine repair shop today takes some time to perform an evaluation of each shop. Just finding one can be a challenge in itself at times depending on where you live as many of these shops have shut down as their owners retired.

Here is how to evaluate a small engine repair shop to find one that will take expert care of your lawn mower or other small engine equipment.

  1. Reviews – Do a Google search for the companies that you have located and see what their reviews say. Also check Facebook to see if they have a business page and see what reviews they have there as well.
  2. Certifications – Check their website to see what certifications they have earned. Look for titles such as “Master Service Technician” or MST. You may also see “Expert Certified Technician”. You want to know if they are certified on your engine such as Briggs & Stratton, Kohler, Honda or Kawasaki.
  3. Wait Time – If the shop has a couple of week wait time during the busy spring season, that is another sign that the shop is sought out and busy. Busy is normally good.
  4. Phone Etiquette – Do they answer their phone and can articulate what they can do for you and how they will do it. If they don’t answer, that can be a good sign as they are busy taking care of their clients or it could be a bad sign meaning that they don’t care about your call. This is a hard one to judge without making contact with them. If they are short with you, it most likely means that they are busy and stressed.

These 4 items will help you decide if the small engine repair shop is going to be a right fit for you or if you need to keep looking elsewhere for the perfect shop to fit your needs.

 

Lawn Mower Repair Tips

Fire Comes Out of Air Filter Box on Lawn Mower

Anytime you have a fire on an engine it is a safety problem due to the gasoline tank on the machine. A fire is not easily extinguished if the gas tank ignites and could catch other things on fire around the lawn mower.

With that being said, it is finding out why it is backfiring that is the most important part of this problem. In order for a backfire to occur through the air filter box, the intake valve must be open while the spark plug is igniting the mixture. The intake valve could have some carbon buildup under the valve seat or it could be hanging open because the valve guide is causing it to stick.

Another possibility is that the ignition timing is not correct. If the lawn mower blade has contacted something such as a root and this is a push mower, the flywheel key may be partially sheared and cause the timing to be incorrect. It is also possible that the timing gear has damage to it.

All of these items should be checked out to determine which is causing the problem and eliminate them one by one.

Lawn Mower Repair Tips

Lawn Mower Keeps Dying Right After it Starts

This is a frustrating experience when you are ready to cut your lawn and have made the time to do it. All you want to do is pull the cord or turn the key and get that job over with.

In most cases what you are dealing with is a fuel problem. The carburetor is not allowing fuel to pass through one of the jets and it normally is the idle jet. The main jet could also be partially plugged up or is sucking some debris into it from the carburetor float bowl.

A lack of fuel is causing starvation and the engine is dying because of it so you must get to the root of this problem to find out why. This will often require the carburetor to be taken apart and thoroughly cleaned inside and out. The ethanol in the fuel today will leave a powder like residue when it dries up and this will clog those ports. Dipping the carburetor with the plastic removed in Chemdip is one such way to clean them very well.

After you have cleaned up your carburetor, reinstall it and test your engine to see if it cures the problem with it dying right after it starts. If it does not, you may have to replace the carburetor but also check your air filter to ensure that it is not plugged with dirt and debris.

Lawn Mower Repair Tips

Lawn Mower is Vibrating Excessively

You can really tell on a push mower if something is out of whack. When you start up the mower on a concrete surface and it wants to jump around rather than sitting in one place. This is a sign that something is out of balance. You could have hit something with the lawn mower blade and bent either the blade or the crankshaft on the mower. You could also have a cracked blade or a piece missing from it.

You could also have a loose lawn mower blade that is causing this vibration. It is something that is rotating and is not in proper alignment that causes it to vibrate excessively. This rotation will cause it to jump from side to side and can be dangerous if the mower gets out of control.

This vibration situation should be checked out as soon as possible to see what is causing it and a repair recommendation. A small engine repair shop can identify what this issue is and find a solution for you so that your lawn mower will be safe to operate once again.

Lawn Mower Repair Tips

Lawn Mower Has No Fire

So you don’t have any fire or spark in your ignition system and your lawn mower will not start. That is one of those necessary things to have for your internal combustion engine is a good clean spark.

Without spark or fire, nothing happens and you must have that spark at the right time of day. The ignition system in a lawn mower cycles thousands of times when you use it and it will go bad eventually due to these cycles and the stress of heat. The ignition coil is tucked underneath a cover and it gets pretty hot in there.

You can test your ignition coil by unhooking the black or gray kill wire that is attached to it. But be cautious as you will not be able to shut off the engine with the kill wire unhooked!

If you do get spark, then you know that the ignition coil is good and the problem is in the kill wire system and it is shorting out or a switch is not working properly.

Check all the wiring and switches to find which one is causing the problem and repair it.

Lawn Mower Repair Tips

Lawn Mower Engine Surges Up and Down

The engine revs up and then down and up and then down and it doesn’t stop and is downright annoying not to mention that it affects the power output of your lawn mower.

This surging is normally caused by a fuel problem or more specifically, a lack of fuel problem. Something is preventing the gasoline from getting into the engine.

Most likely it is a plugged up idle jet that is causing the fuel not to get into the engine. Idle jets are smaller in size and plug up more easily. So the carburetor will need to be taken apart and thoroughly cleaned. You also want to make sure that there is no air leak where the carburetor attaches to the engine or in the intake as well. An air leak will cause this surging as well.

Now you can reassemble your carburetor onto the engine and then test it to see if it has fixed the problem. You should have no more surging and it should run smooth like it should in normal operation.

If it does not, you may have to replace the carburetor as that is the best course of action if you cannot get it completely clean.

Lawn Mower Repair Tips

What Kind of Gas Do I Use In My Lawn Mower

This is a very common question and many different people will have different answers.

First, I like to seek out what the engine manufacturer recommends as they have spent hours and many dollars determining the best gasoline octane rating to put in your lawn mower engine. Gasoline is pretty much the same except some companies put different additives in it to help it burn cleaner and keep your engine parts such as your fuel injectors clean as well.

What we are concerned about is the octane rating for the gas. There are normally 3 or 4 different octanes at your local gas station. You will see 87, 89, 91 and 93. 93 would be referred to as Premium and some people swear by using Premium in all their small engine equipment.

What fuel you use in your lawn mower is decided by the compression ratio of the engine. In a high compression ration such as 12:1, you would use Premium gasoline to prevent the engine from knocking or pinging under a load such as driving your car up a hill.

Most lawn mower engines are low compression engines, so 89 octane gasoline is perfectly suited for them and will provide the most power for this application. So, save your money and buy 87 and if you have access to non-ethanol gasoline, opt for that instead.

Lawn Mower Repair Tips

Lawn Mower Starts Slowly

When you have a hard starting or slow starting lawn mower, the engine begins to turn over slowly and then it finally gets up to speed. This is a sign that the lawn mower is developing an engine problem and it should be checked out as soon as possible. If not, you will have a lawn mower that does not want to start up.

If your lawn mower doesn’t start, well, you won’t be getting much grass cut today! There could be many different things that prevent your lawn mower from starting normally. The grass could be clogging it up if it is a self-propelled or push lawn mower or your could have a carburetor choke problem that is giving you a slow start.

Check both of these items to ensure that you the choke is closing when you try to start and that there is nothing slowing down the lawn mower blades or the PTO shaft on a riding lawn mower.

The choke should gradually open if it is an automatic choke as the engine is starting. If it does not and hangs in the closed position and you see black smoke coming from the exhaust, the choke is definitely the problem here.

Lawn Mower Repair Tips

How To Troubleshoot A Lawn Mower Ignition System

If you believe that your lawn mower does not have any spark, a thorough test of the ignition system is in order.

There are two main times that a lawn mower will not develop spark.

The first is during the initial startup and the second is after the lawn mower has been running for a while.

Let’s start with no spark on startup. You attempt to start the engine and believe that there is no spark. Obtain a spark tester and place it in line with you spark plug wire. Crank the engine over and see if there is spark. If you see a bright blue spark, then the problem is not ignition related. If you have no spark, disconnect the black or gray kill wire that is plugged into the ignition coil. With this wire disconnected, if the engine starts, you will not have a way to shut it off, so plan for that! If the lawn mower does start, then the problem is in the kill system circuit and that will need to be inspected to find out the source problem.

If the lawn mower was running for a while and then you lose spark, install the spark tester to determine if you have a no spark condition. If you have no spark, the most likely item that will cause this is a bad ignition coil. Replace the coil and retest the lawn mower for spark.

Lawn Mower Repair Tips

Lawn Mower Keeps Running Low on Oil

Is your lawn mower using more oil than it should? Are you not seeing any leaks or no smoke coming out of the exhaust?

Any internal combustion engine is going to use oil over time. As your engine is running, oil will seep past your piston rings and be burned up in the combustion process. It can also evaporate as well. It really doesn’t matter whether you are using conventional or synthetic oil as they both will burn or evaporate over time.

If the oil usage is excessive, then something must be done to correct the problem. The lawn mower engine must be given a leak down test to determine where the oil leak is coming from. It could be something as simple as a valve guide oil seal or more complex like the piston rings. A leak down test will tell you what the problem is and get you on the right track to troubleshooting this problem.

Once you know exactly what the nature of the high oil consumption is, then you can repair or replace those components and test the engine to be sure that you have resolved them.