Home / News

Common problems with small engines

Common problems with small engines

Table of Contents

At the heart of every power tool, garden mower or outdoor equipment is a small motor, the unsung hero that brings life to our machinery. However, like any other piece of equipment, these engines require regular inspection and proper maintenance. As the weather changes, the engine is likely to be affected.

In this article, we delve into the world of small engines, unearthing common problems that can arise and how to restore engine performance. Whether it’s a fuel problem causing your engine to hiss, a dirty air filter killing your machine, or a recoil starter failure preventing you from starting your day, BISON can help.

common problems with small engines

Common problems with small engines are listed below.


Every engine needs fuel to work. However, fuel can also damage the engine. When people choose the wrong fuel for an engine, it damages it no matter even if it’s in warranty.

How does fuel cause problems for small engines?

First, some people use dirty fuel and have small pieces floating around. You may ignore these tiny parts and keep running on fuel. These tiny pieces get into the carburetor and clog it. To fix this, you can use a filter to remove the tiny debris floating around. Afterward, you can use this fuel for your engines.

Another problem with fuel is that people store it, and it ages. In turn, using old fuel often damages engines and equipment. BISON’s small engine recommends using fuel stabilizers for old fuels or looking for ethanol-free fuels.


The engine will fail if the carburetor fails to mix the fuel and air properly. If the carburetor gets dirty, it can easily clog, preventing it from working properly. Avoid cleaning the carburetor yourself, especially if you are new to it. Have a technician inspect and learn how to clean and adjust a two-stroke or four-stroke carburetor.

Air filter

The air filter collects dust and grime that protects the engine. When these filters collect so much dirt, it prevents the engine from taking in air and can overheat.

What can you do?

  1. Let the machine rest.
  2. Check the filter for debris and dirt.
  3. Clean it thoroughly.
  4. Air dry or blow dry it off.

If the engine does not improve after cleaning the air filter, replace it with a new one.


Ropes play a vital role in small engines, especially in generators. It can shatter when people pull it too forcefully. To prevent the rope from breaking or fraying easily, just pull gently.

Spark plug

The spark plugs start the magic between the engines. To create a spark between engines, it needs fuel, oxygen, and spark to initiate combustion that drives the pistons. These components work together to keep the engine functioning. However, if spark plugs suffer from carbon deposition problems, this hinders their ability to start the engine.

What should I do?

  • Clean the spark plugs with an emery board.
  • Check the gap.
  • Replace spark plugs.
replace spark plugs

Recoil starter

People frequently believe that when they grab the handle, it will immediately kick in. However, when the recoil starter doesn’t move, it could be broken. Other times when people grab the handle, it snaps immediately.
Remember that the rope and handle bones are connected. The rope bone is connected to the recoil starter bone. However, the engine won’t start if the recoil starting bone is damaged.
To fix this, you can repair the recoil starter or purchase a new one.


Valves are an important part of an engine, like spark plugs and ropes. It will bend, burn and corrode. When a valve ruptures, it can cause the following problems:

  • Poor fuel efficiency
  • Power reduction
  • heavy emissions
  • Too much vibration
  • Power loss
  • Backfire

Most solutions involve consulting a professional to examine the cause of the problem. Avoid repairing it yourself, as this may aggravate the damage.


Washers reduce damage, especially on mounting surfaces. It helps seal the gap to prevent further damage. If the engine fails, the owner needs to check the clearance, especially if the cleaning process is interrupted in the middle.

To repair gaskets, prior knowledge, and experience in repairing engines aid and speeds up the process. A bad gasket cannot be repaired, so it is best to replace it with a new one. Maintenance is especially helpful if you clean the dirt thoroughly and install it properly.

Before installing a new gasket, remove the old gasket to avoid scratching the mounting surface. Check the new gasket and make sure it is in top condition. Don’t scrape off the old gasket with a knife or stick. Use an appropriate tool, such as a gasket scraper, for disassembly. Otherwise, seek professional help.


In the intricate maze of small engines, understanding common problems and their solutions can be a game changer. From fuel issues to gasket failures, we’ve shed light on these often overlooked components. From the humble rope to the all-important spark plug, each component plays a vital role in the engine’s symphony.

Armed with this knowledge, BISON hopes you will now be better able to troubleshoot any engine issues you encounter. As a leading small engine manufacturer in China, we are proud of our strong production capacity and excellent after-sales service. Contact us now to find out more about our products and services.

bison engines

Most Popular Posts



Related Posts

Can’t get enough?

Subscribe for exclusive offers and updates on new arrivals