7 Things To Do When Lawn Mower Runs Rough

Lawnmowers are meant to run smoothly, but when they don’t, the culprit is somewhere hidden inside the mower itself.

If you’ve ever wondered why your lawn mower runs rough out of nowhere but couldn’t get the solution, this article is a must-read.

Although the problem is small, an ordinary spark plug change won’t, unfortunately, help in killing the cause permanently.

Here’s a quick breakdown of some of the useful solutions to kill the problem from its root.

Scenario #1

Lawn Tractor Runs Rough

Because of its huge size, treating even a small problem in lawn tractors sounds like a big deal. If you’ve noticed that your lawn tractor runs rough, it’s high time to find the cause of the problem. 

Cause

The most common cause of the problem “lawn tractor engine runs rough” is possibly a dull, dirty, or damaged spark plug.

However, this leads to disturbance in the ignition system as the air doesn’t pass through the chamber as effectively as before.

Solution 

Here is a list of some common solutions for the problem mentioned above. 

1. Replace the clogged or dirty air filter with a new one. 

2. Replace the blocked vent cap for smooth passage of air. 

3. Change the gasoline in the mower with a high-octane quantity.

Scenario #2

Husqvarna Lawn Mower Sputtering 

Sputtering sound from a lawnmower is pretty much common to encounter as long as you’re there’s a fault in the engine. If the problem doesn’t solve even after the spark plug changes, you can follow the above solutions. 

1. Fix Spark Plug

Create enough spark plug gaps with the help of a spark plug gap gauge. However, you can fill the extra spark plug gap with the use of carbon.

2. Clean or Replace The Air Filter 

A dirty, clogged, or damaged air filter is more than half of the time the cause of a lawnmower running rough. Either clean the filter manually or replace it with a new one with some handy tools.

3. Check Fuel Filter

The fuel filter in your lawnmower is responsible for allowing the flow of gasoline to the engine. Therefore, a damaged fuel filter will waste excessive fuel, causing your lawnmower sputtering problem.

To treat this problem, simply change the dirty or damaged fuel filter with a new one, so the engine gets a smooth passage of gasoline.

4. Change Gasoline 

The gasoline you buy from the market comes with a specific life expectancy depending on the composition.

Such as, gasoline with 10% ethanol will probably lose its volatility in a few weeks, drumming up the carburetor.

In case you use expired gasoline, chances are that your two-cycle engine may cause the lawnmower to sputter. 

The best and easiest way to solve this problem is by increasing the shelf life of gasoline. The longer gasoline will last, the lower the chances of lawnmower sputtering.

For this reason, it’s best to use ethanol-free gasoline along with a fuel stabilizer in order to increase the shelf life by a few more weeks.

What To Do When Gasoline Expires?

Once the gasoline in your lawn mower has expired, drain the gas tank and run the mower for a few minutes to soak up all the expired gasoline, which may cause black smoke, but there’s nothing to worry about.

What Are Some Of The Most Common Causes Of Lawn Mower Runs Rough?

1. Clogged Carburetor

When you leave the fuel for a long time, the sticky particles in the fuel eventually clog up the carburetor, causing the lawn mower engine to sputtering sound.

2. Spark Plug

When the insulator is cracked, it damages the spark plug, causing the engine cranking, which should be replaced as early as possible.

Fuel Filter

 Clogged fuel filters are another common cause of lawn mower runs rough, clean the air filter with dirt and sticky leftovers.

FAQs To Ask When Your Lawn Mower Runs Rough

Why Does My Engine Cycle Running Speed Up And Down? 

If your lawnmower engine is causing a sputtering sound, the problem probably lies in the fuel flow that may be disturbed or damaged.

Can I Use A Carburetor Cleaner To Clean The Build-Up Of My Carburetor? 

Yes, you can. There are a number of options in carburetor cleaner available to choose from.

All you have to do is detach the carburetor from the lawnmower and drop a few drops of the cleaner into the carburetor.

Next, let it rest for a few minutes, use a clean cloth to remove all the build-up, and attach the carburetor to the lawnmower.

What Causes A Rough Idle In My Lawnmower? 

Several causes can cause the rough idle on your lawnmower, and the most common one is the failure in the ignition system, leading to lawnmower engine sputtering sound.

To fix that problem, take the spark plug out of the lawnmower, clean it from inside and outside and fill the gap.

Why Does My Lawnmower Cause A Wheezing Sound? 

If you’ve witnessed your lawnmower wheezing or lagging, the culprit is most probably the dirty or clogged air filter.

To fix that up, clean the build-up in the air filter with a screwdriver or any pointed tool and shake it again to eliminate the lagging sound.

5 Healthy Practices To Treat A Lawn Mower That Runs Rough 

Like any machine, facing lawn mower problems is inevitable, but there’s a way you can reduce the likelihood of your lawn mower runs rough.

1. Change the expired gasoline once every two months or use a fuel stabilizer to increase its shelf life and store it fresh. 

2. Replace your carburetor, air filter, fuel filter, and spark plug to allow easy passage of gasoline to and from the engine. 

3. Check the thickness of oil every time before starting the lawnmower to prevent the over-spillage of oil. 

5. Use a hard-bristled brush to scrub all the mess of the air filter every once in a while.

6. Spray a quality carburetor cleaning to clean the residue of the fuel before it sticks to the surface.

How Many Times Does A Lawnmower Engine Idle? 

Due to the difference in torque, every lawn mower engine has a different rpm for idling. On average, a lawnmower engine should idle around 1,200 to 2000 rpm, which may increase or decrease with respect to the air supply into the engine.

Why Does My Lawnmower Run Then Stall?

If your lawnmower runs for a few minutes and then stalls, it’s probably the problem in the idling that shuts off the mower.

Look into the solutions mentioned above to fix the problem and ensure smooth lawn mowing. 

Why Does My Lawnmower Cut Out After Startup? 

If your lawnmower cuts out after startup immediately, the most common causes are a dirty & clogged carburetor, damaged spark plug, clogged air filter, which limits the passage of fuel to the engine.

Why Won’t My Toro Lawn Mower Start? 

Toro is one of the oldest lawn mower brands and is often a hassle when it comes to starting. If your toro lawn mower won’t start, the common causes can be.

1. Expired gasoline

2. Sticking valves

3. Plug Wire off

4. Coil fault

5. Blocked air filter

6. Plug wet

7. Shear-key fault

Conclusion 

Although it’s common to face the problem ”lawn mower runs rough, there are a number of solutions that can help you in the long term.

Whether it’s the dirty air filter or damaged spark plug, these solutions will help you bring your lawn back into shape without calling for a professional lawn mowing service.