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How to un seize a riding lawnmower engine. With Helpful Tips

One may face many technical problems from time to time if he owns a riding lawnmower. A seized lawnmower engine is, however, one of the rarest of problems. If you do not want to take your Lawnmower to the mechanic because you fear that he might charge more, don’t worry. This blog will help you distinguish the damaged parts, replace them, and test them, all at a home scale.

A lawnmower engine is usually a sturdy component. A seized engine is usually due to the piston and rings sticking in the bore. With the help of some freeing fluid or cleaner, this problem can be solved. However, there might be other contributing factors to this too. Here we take you through them all.

How to un seize a riding lawnmower engine:

  • Step 1: Remove the spark plug
  • Step 2: Clean the combustion chamber with some cleaner
  • Step 3: Open the head and gently tap the piston cylinders
  • Step 4: Check the motor oil
  • Step 5: Test the blades and close all the components

We shall provide in-depth details of the steps mentioned above, like what sort of tools you need and any complexities you might face. Please stick with us as we go through all the potential issues and troubleshoot each of them.

Steps to Un Seize a Riding Lawn Mower Engine:

A riding lawnmower engine may get seized after you de-winterize it due to such distant usage. The seized engine may be due to the parts that are stuck or due to the machine’s absence of motor oil. The procedure below explains all the necessary steps to deal with the situation.

● Step 1: Remove the spark plug:

Whenever a defect occurs related to the internal parts of a lawnmower, removing the spark plug is the first step. The spark plug is removed before cleaning the rest of the parts for two purposes. One is so that no accident occurs when one is pulling and cleaning the cord. The second is to clean the spark plug itself.

To do this, tilt the lawnmower body to a side so that its side now faces the roof. With the help of a plier, unscrew the spark plug because it may be hard to remove it by hand (seized up chamber). Now, using a feeler gauge, you may check the gap between the spark plug terminals. Compare it with manual reading. Now, either clean the plug or replace it.

● Step 2: Clean the combustion chamber with some cleaner:

Through the removed spark plug hole, you can access the piston cylinders and the combustion chamber. You can quickly get aerosol sprays like “Blaster PB” or “WD-40” from a local hardware store. When you buy them, do get yourself a pair of safety gloves as these might be toxic to spray, hence injurious to health. Now, through the hole, flood in an available amount of the cleaner spray and let it rest there for a couple of hours at the least.

The cleaner spray acts as an anti-rust and lubricating agent. It removes the clog built up in the chamber. After a few hours, let the cleaner fluid drain out from the spark plug hole. Now, try to move the blades manually. Make sure that while rotating them, they should be rotated in their natural directions. You will feel lesser resistance to the movement now.

An additional step can be to pull the cord and see the blade’s rotation. This may further give some idea about the extent of seizing in the engine. Pulling the card will produce little motion in the lawnmower blades, a sign for a seized up engine.

● Step 3: Open the head and gently tap the piston cylinders:

Sometimes, only using a cleaner doesn’t solve all of the problems as the riding Lawnmower may have been idle for a longer time. In this case, remove the seat to expose the head of the engine. Opening the head with a screwdriver or wrench will allow you actually to see the piston cylinders. The engine may be blocked and may require an internal push start.

So, hit the piston head preferably with a wooden hammer. Tap it gently as it moves down. This pretty much solves the problem. Besides, check the piston rings, lubricate them. Check for any damaged seals, take no risk, and replace them. Clean the cylinders and remove any dirt or debris that has hardened up and is stuck. Throw in some cleaner spray to moisten the dirt and clogged up the oil. Clean it and let it dry for a few hours.

● Step 4: Check the motor oil:

We have already taken you through the basics. These were easy to solve. Now, a more complex issue that may require more of your focus is here. In all types of seized activities, the one that is caused by running the engine on an insufficient motor oil spray is the most serious.

Through the removed piston head, disintegrate the crankshaft. Same as before, using a wooden hammer, give the cylinders a strike to thump them out. Also, rotate the crank. This helps remove the crude oil that got stuck up in the moving parts. Use a cleaner to purify them thoroughly.

Remove the connecting rods and seals. Clean them too, as crude oil may still be stuck there. Give the insides a thorough washing. You can use petrol to wash it too. Now, let the engine bask in the sun and dry up naturally. Add lubrication to each component as you close up the casing and side by side, give the lawnmower blades a gentle thrust to make them move.

● Step 5: Close all the components:

After all this day long hustle, most of your technical work is done. However, closing all the components is the essential key for prolonged safety from damage. After all the parts have been lubricated and dried up, conceal them as they were taken out. Ensure the seals are tight, the crankshaft is fixed, and piston cylinders are’ t free. Close the head and fix the seat back in its place. Add new motor oil to your Lawnmower. Remove the old crude fuel. Add new fresh fuel, preferably with some anti-clogging agents mixed in. For a week on, use the mower gently and regularly so that engine gets back to its full potential.

Even if, after all these steps, the blades aren’t softening up as much as they should, it is time to call in an expert.

Related Questions:

1) Why should I use a wooden hammer or wood to strike the piston cylinders?

The combustion chambers are quite sensitive parts in terms of dimensions and sensitivities of pressure, are, and volume. A regular hammer, if used to thump the cylinder, may cause the cylinder to disorientate. At the very least, it can cause a dent in the cylinder or piston due to its rigid nature. Deformities can cause a change in the critical pressure or volume of rotating machines, which can be very dangerous.

A wooden hammer, on the other hand, is rigid and flexible at the same time. You may have observed that all denters use a wooden hammer to remove the dents too. This allows them to give a considerable power strike keeping the flexibility and geometry intact.

2) How can you tell if your lawnmower engine is seized?

To tell if a lawnmower engine is seized, you have to follow through a few steps. Start by removing out the spark plug to expose the channel to the combustion chamber. If a lawnmower with a removed spark plug still jump-starts, its valves may be worn out and hence, need replacement. However, if the engine doesn’t run and the blades are rigid and don’t turn over, it is seized. A seized lawnmower engine has locked cylinders, blades, and pistons.

3) Why removing the spark plug is necessary?

When operating on a riding lawnmower with sharp blades, precaution is a must. While cleaning, one has to clean the combustion chambers, piston cylinders, and valves. Sometimes, even the cord needs maintenance, so it has to be pulled. So, as a safety measure, it is advisable to remove the spark plug before any Lawnmower action to keep away from any harm.

Final Remarks:

For those who love their hobby of gardening, a lawnmower is the best buddy one must-have. However, after long gaps or after de-winterization, its use may pose some problems in engine activity seizing up. A seized engine doesn’t mean the machine’s death, but it sure affects its life if not addressed. Following the steps mentioned above in definite order, you can efficiently deal with this issue. It may seem huge at first glance, but following the guide will help you step by step. Even after all these steps, your Lawnmower fails to work correctly, and it is better to take it to a mechanic. Happy lawnmowing!

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  1. Shane Wood says:

    I never thought I could troubleshoot my lawnmower engine on my own, thanks for the tips.

    • Allard Vdhooft says:

      Glad the tips helped, Shane! Remember, regular maintenance is key to keeping your lawnmower running smoothly. Happy mowing!

  2. Irma Oliver says:

    Can I do these steps even if I have no prior experience with lawnmower engines?

    • Allard Vdhooft says:

      Yes, you can follow these steps even if you have no prior lawnmower engine experience. The guide provides detailed instructions to help you troubleshoot the issue step by step. Good luck!

  3. Sharlene King says:

    This was so helpful! I fixed my lawnmower engine thanks to this guide.

    • Allard Vdhooft says:

      Glad to hear that the guide helped you fix your lawnmower engine, Sharlene! Feel free to reach out if you have any other questions or need more assistance. Happy mowing!

  4. Marjorie Martinez says:

    Great explanation on why removing the spark plug is necessary for safety.

    • Allard Vdhooft says:

      Thank you, Marjorie! Removing the spark plug is essential for safety when working on a lawnmower engine. Stay tuned for more detailed steps on how to troubleshoot and fix seized engines.

  5. Bryan Taylor says:

    After cleaning the engine, should I let it dry in the sun or use a fan?

    • Allard Vdhooft says:

      After cleaning the engine, letting it dry naturally in the sun is the best option. This ensures that all components are thoroughly dried before reassembling. Hope this helps!

  6. Felicia Arnold says:

    Great guide! But could you provide more information on what to do if the engine is still seized after following all the steps mentioned?

    • Allard Vdhooft says:

      Thank you for your feedback, Felicia! We will make sure to include more detailed instructions on how to deal with a seized engine in our future posts. Stay tuned!

  7. Charlie Simmmons says:

    I never knew I could do this myself, saved me a trip to the mechanic.

  8. Roger Franklin says:

    What should I do if the engine is seized after trying all these steps?

    • Allard Vdhooft says:

      Hi Roger, if the engine is seized after all these steps, try using a freeing fluid or cleaner to solve the issue. Check for other contributing factors as well. Good luck!

  9. Cory Chavez says:

    How long does it usually take to unseize a lawnmower engine?

    • Allard Vdhooft says:

      Hi Cory, unseizing a lawnmower engine usually takes a few hours to a day, depending on the extent of damage. Follow the steps mentioned in the blog post for a successful repair.

  10. Vickie Hall says:

    This guide is so detailed, thank you for explaining everything so clearly.

    • Allard Vdhooft says:

      Thank you for the positive feedback, Vickie! I’m glad you found the guide helpful. If you ever have any questions or need further assistance, feel free to reach out.

  11. Christy Kim says:

    Do I need to replace any parts of the engine if it’s seized?

    • Allard Vdhooft says:

      Thank you for your comment, Christy. Typically, you may not need to replace any engine parts if it’s seized. Follow the steps mentioned in the blog post to remedy the situation.

  12. Leah Douglas says:

    How often should I clean my lawnmower engine to prevent seizing?

    • Allard Vdhooft says:

      To prevent seizing, cleaning your lawnmower engine every 25-50 hours of operation is ideal. Following the steps mentioned in the blog can help maintain your engine’s health.

  13. Riley Boyd says:

    Is there a specific type of motor oil I should use for my lawnmower?

    • Allard Vdhooft says:

      You should use SAE 30 motor oil for your lawnmower. It is specifically designed for small engines like lawnmowers. Happy mowing!

  14. Terra Burke says:

    Can I use any other cleaning spray apart from Blaster PB or WD-40?

    • Allard Vdhooft says:

      Yes, you can try using a penetrating oil or cleaner to unseize your lawnmower engine. Make sure to follow the steps carefully for best results. Good luck!

  15. Cindy Griffin says:

    Thank you for breaking down the steps, makes it so much easier to follow.

    • Allard Vdhooft says:

      Thank you for your kind words, Cindy! I’m glad that the breakdown of steps was helpful to you. Let me know if you have any other questions.

  16. Bill Neal says:

    I had no idea it was possible to tap the piston cylinders to unseize the engine.

    • Allard Vdhooft says:

      Glad to hear you found the tip helpful! If you have any more questions or need further assistance, feel free to reach out. Happy lawnmowing!

  17. Ashley Lowe says:

    What are some signs that my lawnmower engine might be seizing up?

    • Allard Vdhooft says:

      If you are facing signs of your lawnmower engine seizing up, follow these steps carefully to troubleshoot and resolve the issue at home. Hope this helps!

  18. Ronnie Welch says:

    How can I prevent my riding lawnmower engine from seizing up in the future?

    • Allard Vdhooft says:

      Ronnie, to prevent a riding lawnmower engine from seizing up, regularly maintain the motor oil levels, clean the combustion chamber with a suitable cleaner, and follow the steps outlined in the blog post for maintenance.

  19. Anita Peterson says:

    I’ve bookmarked this page for future reference, really appreciate the help.

    • Allard Vdhooft says:

      Thank you, Anita! We are glad you found the information helpful. Feel free to reach out if you have any more questions. Happy mowing!

  20. Sean Murray says:

    Should I wear any protective gear while working on my lawnmower engine?

    • Allard Vdhooft says:

      Hi Sean, it’s best to wear safety goggles and gloves when working on your lawnmower engine. Safety first!

  21. Terry Barnes says:

    Thank you for including pictures with the steps, really helps understand the process.

    • Allard Vdhooft says:

      Thank you for the positive feedback, glad you found the pictures helpful. Stick with us for more detailed guides on maintenance and troubleshooting!

  22. Paula Lane says:

    This guide is a lifesaver! I was about to give up on my lawnmower.

    • Allard Vdhooft says:

      Thank you for your feedback, Paula! I’m glad the guide was helpful in saving your lawnmower. Let me know if you need any more assistance.