Lawnmower Juddering

Why Is My Lawnmower Juddering?

Lawnmowers are one of the most important pieces of equipment that you can own, especially if you actively participate in maintenance around the house! With the need to use it almost every other week, you might need help keeping it up to the mark at all times to avoid any troubles.

If you have noticed that your lawnmower is juddering more than usual these days, turn off the engine immediately as there might be a few problems causing it. It is always better to fix any problems sooner so that you may avoid any irreplaceable damages. Juddering in your lawnmower may be due to unbalanced blades or a bent crankshaft, as these are the most common causes. However, there may be other underlying issues too!

Keep reading to find out what they are!

Lawnmower Juddering

Common causes of lawnmower juddering

Unbalanced blades

The most common issue leading to a juddering lawnmower is unbalanced blades. The excessive vibration in the lawnmower may be due to unbalanced weight distribution at either end of the blades when it spins, putting excessive load not only on the blade but the engine as well. This may also result from a blade damaged or sharpened incorrectly; however, to rule out any of these potential causes, you must inspect your blade for any damages or uneven balance and either repair or replace it. Unbalanced or damaged blades might cause potential risks for the operator as well. A blade is easy to examine, repair, and replace; therefore, it must be one of the first things you look for when troubleshooting. With a blade running at 220 MPH, it may be easily damaged by even a slight stroke.  An unbalanced blade may lead to the above-mentioned problems, but it is easy to detect and fix; therefore, you must keep a constant check on it whenever you encounter a strike with a rock or a tree stump just to be safe and to avoid any irreparable damage that might be caused later to the blades, crankshafts of even the engine.

Bent crankshaft

Another cause that might lead to your lawnmower juddering excessively is a bent crankshaft. A crankshaft is the central component of your lawnmower’s engine. It keeps the blade and the engine aligned; therefore, any disruption in it may lead to disruption in the mechanics of the entire lawnmower. Just like the potential damage to the blade, the crankshaft may also have been damaged and bent, which was leading to the excessive shuddering of the engine. The damage may result from the blades hitting an object that they weren’t able to move past, such as a rock or a tree stump. Just like an unbalanced blade, this is also a very risky cause and might lead to potential risk and damages to both the operator and irreparable damage to the engine as well. If you doubt that this might be the cause, discontinue using the lawnmower immediately and seek professional help in repairing the lawnmower.


Apart from these, there might be a few more causes leading to your lawnmower juddering excessively. These causes may be easily reparable by yourself, and they must be a part of your checklist so that you can maintain your lawnmower from time to time to avoid any irreparable damages.

Your lawnmower might require regular maintenance to keep it up to the mark. The engine, blades, crankshafts, and motors are an essential part of the machine and must be in order so that the lawnmower can work seamlessly. To keep it up to the mark, here are a few things that you must keep in check at all times.

Here are few other reasons causing your lawnmower to judder

Obstructed fuel system

Problems in the fuel system may lead to direct and irreparable damage to the engine. You need to keep a constant check on the type and quality of fuel that you use as well as the different components of the fuel system down to the smallest details of the nozzle of the fuel cap as each component holds a significant part in making the engine run seamlessly and without any troubles.

Damaged flywheel

Apart from the crankshaft and the blade, another component that maintains a healthy run of the lawnmower is the flywheel. The flywheel acts as a shock absorber and a cooling fan, and a strike with a hard object may damage the flywheel. If a flywheel is damaged, the lawnmower may vibrate excessively and lead to irreparable damage to the engine.

Engine requires tuning

One of the most important components of the lawnmower is the engine, without which nothing may work. You must keep a check on the engine and keep it well-tuned so that there may not be any fuel leakages or added sputtering and heating up in addition to the excessive vibrations.

Due routine maintenance

Lastly, one of the most important things you can do is to carry out routine maintenance check for your lawnmowers to remain top of the notch and last you a long time!

Lawnmower Juddering


Keep a check on these to help maintain your lawnmower better

Additionally, there are a few more things that may help you maintain your lawnmower up to the mark and make it last a lifetime.

Keep the air filter in check

Air filters are one of the most common problems that lead to unsatisfactory results from your lawnmower. The air filter is quick and easy to clean, and it may be the first thing you look for when troubleshooting what went wrong with your lawnmower. A dirty air filter may need to be replaced after cleaning, but it is a quick job that would save you tons of time when figuring out what went wrong with your lawnmower.

Check the carburetor

Apart from the air filters, the carburetors are also a component that needs to be kept clean as a dirty carburetor may lead to an engine that surges and judders uncontrollably. This might be more difficult than the air filter, but its maintenance may last longer too.

Take good care of your lawnmowers

By now, you must’ve realized that a lawnmower requires maintenance and proper care to last longer; therefore, you must ensure that you use the right type of oil, do routine checkups, and replace any damaged parts that might lead to potential risks for the operator and the lawnmower itself!  A lawnmower is an important tool for home maintenance and might be one of your favorite hobbies as well, so make sure you do it right every time!


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