How to Unseize a Riding Lawn Mower Engine? How to Tell Its Seized?

You head towards your riding lawn mower one morning, start the engine and notice a tricking grinding sound. The mower automatically switches off and the blades are stuck. You try to rotate the blades manually but they won’t budge.

What is wrong with your lawn mower? The answer is straightforward. The engine is seized. The engine is a crucial part of your lawn mower and if the engine is seized your lawn mower will stop working.

But how to tell if riding lawn mower engine is seized or if there is some other issue? And if it is seized then what should be done about it? Let us figure it all out for you.

How to Tell if Riding Lawn Mower Engine is Seized?

While insufficient oil supply is the principal factor behind a lawn mower seizure, there could be other reasons too. Following are the signs that your lawn mower engine is seized.

  • Engine sounds rough
  • Engine does not start
  • Blades do not move and are stuck
  • The cylinder and piston are fixed
  • Low oil level
  • Deteriorated fuel quality

The above list may sound overwhelming but do not worry. Let us first break the things down into simple steps to help you analyze the cause of the seizure.

Steps to figure out the reason for the lawn mower engine seizure

sign that a lawnmower is seized

To rectify the engine seizure problem you first need to detect the reason for the same. Below we list down the components that you should check which may be the probable cause for the lawn mower engine seizure. We will then discuss the solution for the same.

Engine sounds rough

If your mower is seized then the engine will not start. If you do manage to start the engine then it will switch off on its own. The little energy that it is left with will make a grinding noise which is because of the engine parts colliding with each other. The typical sound is a huge gurgle that immediately shuts down the engine and is a clear indication of an engine seizure

The engine does not start

In the first case, you happen to start the engine. It then makes a sound and immediately shuts down.

In the second case, you are not able to turn on the engine. The cord feels tightened, the blades are stuck up and the engine shouts out that it is dead.

You try to pull the cord but the engine does not start. Your engine needs to be unseized to get it back to working condition.

Blades do not move and are stuck

A stuck blade is a clear indication of a seized engine. Stuck blades are jammed blades that make it difficult to rotate the blade with your hand or with a tool. The blades are fixed and do not move.

This is because of some internal component that jams it up. The stuck blade will shut the engine down causing a seizure.

The cylinder and piston are fixed

An internal jammed part may also cause lawn mower engine seizure. In most cases, it could be the piston that is stuck in the cylinder. This may happen if the engine was exposed to a muddy water puddle where the moisture came in contact with the engine causing the engine to seal and the valves to explode.

The seals when damaged will free the piston causing oil wastage. The piston now is unlubricated which gets stuck in the cylinder. The main combustion chamber is seized and does not produce energy.

Remove the spark plug to check it as a precautionary measure. Remove the engine head to expose the engine assembly pathway. This will let you confirm the reason for the engine seizure.

Low oil level

Oil shortage in the engine is also a major concern that leads to engine seizure. A decrease in oil levels can lead to major issues. When the oil that lubricates the piston depletes then the piston gets jammed because it lacks lubrication.

So you need to continuously keep track of the oil level in the chamber and gas tank.

To check the oil level, get a gas container and detach the fuel line attached to the carburetor. Place the gas container below the tank and drain out the gas. When the tank is empty, use a flashlight and check the debris and light beads to find out any holes and cracks. Remove the slack debris using a baster and check out the oil gauge and cylinder walls to see if they are lubricated.

If the oil level is depleted then this indicates a seized engine

Deteriorated fuel quality

If your lawn mower engine is seized then this will also indicate a low fuel quality in the chamber. This is not the primary indication but an add-on. It happens because the crude oil present in the chamber gets clogged up which leads to improper combustion. It lets the debris get stuck up in the chamber and leads to piston working failure.

The above are clear indications that your lawn mower engine is seized. If you notice any of these then read below to understand the ways to unseized your lawn mower engine.

How to Unseize a Riding Lawn Mower Engine?

how to fix a seized lawnmower enginee

After you have identified the reason it is time to unseize the riding lawn mower engine. For this, you will need:

  • A penetrating oil spray can
  • Engine oil

Here are the steps to follow:

  1. Drain the oil from the mower. You will also need to buy a penetrating oil spray can. Remove the spark plug from the engine and face up the spark plug hole to fix the seizure.
  2. Spray a good amount of the penetrating oil in the mower hole plug and wait for the oil to soak fully. Soak it for at least an hour in the combustion chamber.
  3. Now reset the engine to its original position and try to move the engine’s piston up. Grip the blade and move it in a forward and backward direction. This reduces the lawn mower engine’s dullness. Keep doing this till the engine movement is free.
  4. Plug the spark plug.
  5. Ensure to buy the engine oil as recommended by the manufacturer and pour the oil into the oil tank till the tank is full.
  6. After you fill oil in the oil tank turn the lawn mower on. Give it five minutes to warm up and your lawn mower should be all set now.

Preventive measures

  • Use gloves to extract the grass, debris, and any old dirt from the blades.
  • Take care to not cause any personal damage.
  • Follow the manufacturer’s maximum and minimum oil level and never overfill the oil tank. An inaccurate oil level will cause oxidation of the internal components which makes it difficult to start the mower.

Regular maintenance is the key

  • The lawn mower engine seizes if the mower has been left unused for a long period.
  • Low oil level, improper oil level, and lack of lubrication are other reasons for seizure which also decreases the durability of the engine.
  • Regularly maintaining the engine and taking care of lawn mower saves you from the hassle and also increases the longevity of the vehicle. It is advised to change the lawn mower engine oil in scheduled intervals.
  • Keep the internal engine component oxidation level to a minimum which can be done by running the engine at least once a year.
  • The lawn mower should be stored in a shed or a garage so that is it is not exposed to the external elements.

All these are some basic preventive measures that decrease the chances of a lawn mower engine seizure.

Final verdict

It is no rocket science to identify the reason behind the riding lawn mower engine seizure. Once you spot the issue you may want to rectify it yourself or get professional help. Regular maintenance is the secret to avoiding engine seizures. However, if the engine is seized and the above steps fail to work, then this is an indication that your lawn mower engine needs replacement.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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