Why Your Riding Lawn Mower Is Losing Power


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Riding lawn mowers are remarkably reliable and tend to last for years, so it’s easy to get concerned when they start to feel sluggish and don’t seem to have the power they once had. If you’re mowing the lawn and feel like your riding lawn mower just doesn’t have the power it did when you first bought it, don’t just run out and buy a brand-new mower.

There are several reasons for this reduction in power, and not all of them mean that your mower is kaput and can no longer be used. If you’re wondering about some of the reasons your riding lawn mower is losing power, below is some information that can be helpful to you.

One of the First Things to Check

Any gas-powered engine is going to need three things to start the combustion process: air, fuel, and a spark to ignite the air/fuel filter. Riding lawn mowers, therefore, need the correct amounts of air or fuel to run properly. If they don’t receive it, the engine can run sporadically or even stop running altogether. A spark that is weak or isn’t started at the right time can produce the same symptom – a lawn mower that seems to be losing its power.

Make sure you have the right amount of fuel and air and that a proper spark is executed for the lawn mower to run as it should.

Is the Fuel in Your Lawn Mower Stale or Old?

Bad and dirty fuel can wreak havoc on the lawn mower’s engine and cause it to lose power. To make things worse, much of today’s gas is mixed with ethanol, and ethanol attracts moisture over time. This moisture essentially dilutes the gas, and this can happen in as little as 30 days. If your gas is more than one month old, therefore, it could be the gas that’s causing your lawn mower to lose power.

Some solutions include adding a fuel stabilizer to your tank or even using canned fuel that has no ethanol in it, both of which are easy to find. If you do not choose these options, make sure you replace the old gas with fresh gas at least once a month.

Is Your Fuel Filter Clogged or Dirty?

The fuel filter in your riding lawn mower has an important job to do. It removes dirt found in the fuel before the fuel enters your carburetor. When this happens, the fuel filter can actually become less efficient and may even clog. What this means is that the better the fuel filter does its job, the more it is likely to become clogged. When the fuel filter is clogged up, the flow of fuel to the engine is restricted, which can mean a loss of power.

Changing your fuel filter regularly is crucial because this is the only way to make sure it doesn’t keep getting clogged up and affecting the efficiency of your riding lawn mower.

Is Your Air Filter Clogged or Dirty?

Just like your fuel filter, the air filter in your lawn mower can become clogged when it’s doing its job well, which is to clean the air before the air goes into the carburetor. If you don’t change your air filter regularly, it is easy for it to become clogged up and make being efficient a lot harder to do. This is because clogged air filters will not allow the right amount of air into your carburetor, which automatically reduces the power of the engine and makes it run sluggish or even stop altogether.

Just like the fuel filter, however, there is an easy solution to this problem – simply change the filter regularly before it has an opportunity to get clogged.

Are You Trying to Cut Grass That Has Gotten Too Long?

Theoretically, we should never let our grass get too long to mow. But sometimes that only works on paper! In reality, it’s very easy to let the grass on your property get too long, and while you may think that a riding lawn mower is the solution to the problem, that isn’t always the case. For extra-long grass, you may need a tractor instead of a standard riding lawn mower to get it cut properly. If you’re trying to mow through grass that is simply too long, it will affect the power your lawn mower has and make it a lot less efficient.

You can try adjusting the cutting height of your lawn mower, but if that still doesn’t work, you might need a tractor instead to do the job right.

Is the Ignition Inconsistent, or Is There Debris or Oil on the Spark Plug Electrodes?

If your riding lawn mower is losing power regularly, it could very well be your spark plugs. Spark plugs are only meant to last a certain amount of time, so when they reach that point, they’ll need to be replaced. Spark plugs can foul up and amass carbon, dirt, fuel, and oil on the electrodes themselves. The most common symptom of this is an inconsistent spark and loss of power.

If you’ve checked everything else and they seem to be working fine, check your engine’s spark plugs because it could very well be those small items that are causing such huge problems.

Is the Motor Oil in Your Engine the Culprit?

If you have either too little or too much oil in your engine, it can cause you problems. If you have a level of oil that is too high, it can result in froth. Froth is when air is introduced into the lubrication system, which reduces the oil’s ability to lubricate the moving parts. In a way, the engine parts become “stuck” and can’t do their jobs whenever there is too much oil in the engine. On the other hand, when you don’t have enough oil in the engine, the system’s ability to lubricate adequately is reduced, which means friction is increased and a bigger load is put on your engine. This, in turn, means the engine cannot do its job properly and will cause the lawn mower to lose power.

The solution to this problem is simple. Simply add more oil when needed, and make sure you never put too much oil into the engine whenever it needs more oil.

Have You Checked Your Mower Blades Lately?

While most riding lawn mowers work well on flat land, going uphill or even downhill is sometimes a problem. If you’re unable to make it up an incline of any kind, it might very well be your cutting blades. When grass, mud, and other debris get built up on the blades of your mower, they’ll naturally slow down, which means the motor is working much harder to do its job.

If you haven’t done so in a while, make sure you check your cutting blades and underneath the housing for the engine blower to make sure no debris is clogging up somewhere. Cleaning the blades should solve the problem immediately.

Problems with Your Carburetor

A carburetor is there to mix gas and air so that ignitable fuel can power the engine of your lawn mower. When your carburetor is dirty, the fuel vapors that normally give the mower the extra power it needs to go uphill or through other challenging scenarios might not be there to do the job.

How do you take care of this problem? It’s simple! Just clean your carburetor and replace any gaskets or seals that are worn out and out of shape. More often than not, this takes care of the problem, but if it doesn’t, contact a professional to get the choke switch inspected. If something is wrong with the choke switch, it will likely need to be either repaired or replaced altogether. But first, make sure your carburetor is clean and in good shape.

Problems with Your Muffler

Your muffler is where your lawn mower will expel the burned gas and any other vapors, but like other parts of the mower, your muffler can get clogged with fluid and various types of debris. When this happens, the burned gas is unable to exit your lawn mower, leading to many different problems, including a motor that seizes up and stops working. If you ever see colored smoke coming out of your lawn mower, it could very well mean that your muffler is clogged. In this case, the best thing to do is make it a habit to clean your muffler thoroughly at the beginning of every mowing season.

In fact, yearly maintenance is one of the smartest things you can do when it comes to keeping your riding lawn mower fully functional. Check the spark plugs in case they need to be replaced. Make sure all of your filters are clean and ready to do what they’re supposed to do. Make sure your oil and fuel levels are right where they need to be. Clean the lawn mower from top to bottom, including the cutting blades. Store the lawn mower away when wintertime arrives. Taking good care of your lawn mower means it will be there for you when you need it, and regular maintenance is a lot easier than you think.

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