Why Does My Push Mower Lose Power?

You expect consistent output from your push mower throughout the time of usage, but every so often, a mower will lose power. It may or may not shut down completely – this loss could be momentary, or it could be long-term.

Push Mower Lose Power

Courtesy: M01229 via Flickr

Power Loss Due to Dirt

The primary reason your push mower may lose power is often dirt. There are two major locations to check out – the air cleaner elements, and the fuel system.

Grass and dirt can clog up the air filter, if it has one, or block the cooling fins. This will block air from coming in, starving the air-cooled engines of their cooling capabilities. This will cause the engines to bog down and overheat, causing power loss. Clear the debris from the cooling fins to regain the power needed.

The second possibility is dirt and water in the fuel system. This will cause build-up in the carburetor, inefficient combustion, sputtering, and power loss. The only fix is to drain the fuel system, and to replace the bad fuel with fresh fuel.

An Improper Oil Level can Cause You Engine to Lose Power

Both a high crankcase oil level and low crankcase oil level can cause your engine to lose power. A low oil level may mean there isn’t enough to lubricate all of the necessary moving parts, causing them to seize up and cause momentary loss of power or to permanently seize up. A high oil level can lead to the oil getting frothy, introducing air into the lubrication system. The air will reduce the ability of the oil to lubricate, causing metal to rub together and causing the engine to lose power due to excess friction.

Excessive Engine Load

Sometimes you may just be asking too much out of your engine, and this will make the engine bog down. You may be asking your riding mower to take on too steep of a hill with too much weight. Maybe you’re trying to get your mower through grass that is too high or too thick. Whatever the reason, you’ll need to lighten the load – whether literally removing weight, or attacking the area you are trying to mow differently.

Faulty Spark Plugs

A pitted or fouled spark plug will cause inconsistent ignition. Over time, the spark plug can become covered in fuel, carbon, dirt, and oil, preventing a constant spark. This will then cause the mower to skip or miss, and it will lose mower. Spark plugs are simple to remove, clean, and replace, so this should be one of the first places to check. On top of that, spark plugs are often the root of any performance problem, and should be a constant point of maintenance when looking over your mower.

Carburetor Issues

A dirty or improperly-adjusted carburetor will prevent your engine from getting a full supply of fuel, meaning that it will be more likely to lose power and get bogged down, even during less strenuous parts of mowing. You’ll need to remove and clean the carburetor, according to the owners’ manual for your mower.

So don’t let your lawn mower get bogged down and lengthen your mowing day. Make sure to address the problem as soon as possible, as a momentary loss of power can turn in to something more severe and long-term if you allow it to continue unchecked.

About AndrewT

Written by Andrew T for LawnEq - The specialists for Lawn Mower Parts and Small Engine Parts. We offer genuine premium OEM parts for Land Pride, Toro and many more dependable brands.