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Lawn Mower Loses Power under Load

When trimming the yard, washing the deck, or cutting firewood, you need a piece of home equipment that works at its best from the start to the end. When there is a sudden loss of power, it’s difficult for you to continue with the task.

Power loss can be a continuous thing or an ebb and flow, but the outcome of the two variations are the same. While on duty, you definitely don’t like interruptions that chip in a while at work.

Unfortunately, you will probably experience it a little bit if you’re operating with the lawnmower that loses power while under load.

It’s normal for a lawn mower to run slowly and rough if it’s old. However, you would expect a relatively smooth use with new ones. According to experts, consistent lawn mower output is anticipated throughout its life.

Unfortunately, they tend to lose power from time to time; it might shut down completely, leading to temporary and even permanent losses.

What Makes The Lawn Mower To Lose Power?

You may have no problems with your lawnmower on flat ground, but when it’s under load you feel like it’s failing you completely. If your lawn mower always loses power when cutting grass on a slope or uphill, it’s a clear indication that it has a problem.

Troubleshooting as a diagnostic criterion is required to determine why the lawnmower is losing power when mowing uphill and when under load. In most cases, the issue is pretty obvious, and all it takes is a few basic tweaks or standard maintenance measures to get it back in proper working condition.

The common reasons that make lawnmowers lose power include the following;

  • Dirty Blades and the Clogged Air Channels

As you go upward, dirt, debris, and corroded materials can cause your lawnmower to lose power. When the blades are coated with dirt, grass, or any other debris, the oscillations are slowed down, and the engine has to work harder to spin and operate as expected. A clogged air filter might also cause power issues.

The solution of dirty blades and blocked air passage is to clean or replace the mower’s air filter and remove blockages from the blades and below the engine’s blower housing. Before reaching out to any of the mower’s parts, remember to switch it off first.

  • Carburetor Issues

A carburetor works by combining gases and air to produce an ignitable fuel that powers the engine. The gasoline vapors required to offer the lawnmower the additional energy to run uphill and work when under big loads might not be supplied if the mower’s carburetor is unclean.

Servicing the carburetor and repairing any broken seals or gaskets may be enough to fix the issue. If the technique doesn’t enhance the mower’s uphill and under load performance, hire a professional to evaluate the choke switch. If you find out that it’s broken, you’ll have to replace or fix it before using the lawnmower again for another errand.

  • Fuel Problems

Inadequate gas and oil are the most common reasons for power loss when the lawnmower is under load. If the gasoline inside the tank on the mower is significantly reduced, mowing uphill may reduce the quantity reaching the carburetor.

As the mower is leaned back, the gas goes away from the carburetor, causing transmission problems. Your mower may potentially lose power due to reduced oil levels in the engine. You may have dirt or water in the mower engine; in this scenario, the tank must be drained and refilled with new gasoline, or a trained dealer must service the mower.

In addition, you need to make sure that the fuel tank is filled with the right content and the level inside the crankcase is proper. Regular inspection of the fuel tank enhances the mower’s performance.

  • Clogged Muffler

The mower’s muffler is where burnt gas and other fumes are expelled. Debris and fluid blocking the muffler prevent the burnt gas from escaping your lawnmower, causing major issues such as a seized motor.

If your lawnmower has the trend of emitting colored smoke, the muffler is likely blocked. As part of a normal lawn mower maintenance program, clean your lawn mower’s muffler at the start of each season.

  • Ignition Issues

If the spark plugs in the mower are pitted or clogged, they will not ignite the gasoline vapors when the pistons go higher or under heavy loads. With time and use, spark plugs become covered with carbon, dirt, and oil.

It’s essential to examine, change, or clean the spark plugs every season to minimize the interference associated with ignition and power loss.

What You Need to Do If Your Lawn Mower loses Power under Load?

If you’ve a lawn mower machine that is constantly losing power, check the pistons as well as the air filters.

Furthermore, the repair and symptom guides provided in this article will help you determine the specific mower component causing the problem. For more precise repair and maintenance instructions, consult the handbook for your model.

The guidelines given below will help you keep the lawn mower under load work without power loss;

  • The air filter cleans the air entering the lawnmower, keeping the engine running smoothly. Dirt and debris would clog the carburetor’s tiny fuel openings, causing damage to the piston and the cylinder wall.  Check and replace the air filter regularly. Debris will accumulate on the air filter, preventing the necessary amount of air from passing through. When such happens, the engine loses power. Maintenance of your lawnmower’s air filter is simple and should be done regularly. Each mowing season, inspect the filter and replace it when it has revolted.


  • The piston and cylinder generate power. After combustion, the piston pushes the crankshaft. The crankshaft drives the mower’s blade and drives wheels. The explosion creates compression in the cylinder. The piston rings keep the compression in the cylinder; the rings secure the piston to the cylinder walls. A few molecules of oil keep the rings from rubbing against the cylinder. Compression is lost as the rounds wear or the cylinder is damaged. Have trouble starting your lawn mower or it loses power under load? Hire an expert check and correct piston and cylinder configurations.