How Much is a Lawn Mower Engine? A Guide to Costs, Types, and More.

Mowing your lawn is a chore that most homeowners have to face. But what happens when your trusty lawn mower starts sputtering and refusing to cooperate? You might be thinking, “Is it time for a whole new mower?” Or, perhaps, a replacement engine is the more affordable solution.

This guide explores the world of lawn mower engines, breaking down the cost factors, different engine types, and even some tips on DIY engine replacement. Whether you’re facing a repair or simply want to understand the value of your current mower, this article will provide the information you need to make informed decisions.

The short answer: The cost of a lawn mower engine can range drastically depending on the engine type, brand, horsepower, and features. You might find replacement engines for small walk-behind mowers starting around $100, while larger riding mower engines can cost upwards of $1,000.

Understanding the Costs of Lawn Mower Engines

Many factors influence the cost of a lawn mower engine. Here’s a breakdown of some key considerations:

1. Engine Type:

The type of engine in your mower plays a huge role in its price. Here are the most common types:

– Small Engines (Typically for Walk-Behind Mowers)

  • Four-Stroke Engines: These are known for their efficiency and longevity. You’ll find them on most mid-range to higher-end walk-behind mowers. They’re typically priced between $100 to $500 depending on horsepower and features.
  • Two-Stroke Engines: These are usually lighter and cheaper but require a pre-mixed fuel blend. They’re often found on entry-level walk-behind mowers and can cost $50 to $200.

– Large Engines (Typically for Riding Mowers)

  • Briggs & Stratton: A popular and reliable brand, their larger engines for riding mowers can range from $300 to $1,000.
  • Honda: Known for their exceptional durability, Honda engines can be more expensive, often costing $500 to $1,500.
  • Kawasaki: Known for their power and reliability, Kawasaki engines are also in the higher price range, often costing $400 to $1,200.

2. Horsepower:

More horsepower translates to a more powerful engine, and usually, a higher price. For walk-behind mowers, you’ll typically find engines ranging from 3 to 7 horsepower. Riding mowers often have engines with 10-20 horsepower or even more.

3. Features:

Additional features, such as electric start, fuel gauges, or specific emission control technologies, can increase the cost of a lawn mower engine.

4. Brand:

Certain brands, like Honda and Kawasaki, are known for their high-quality, durable engines, which often come with a higher price tag.

DIY Engine Replacement: A Cost-Saving Option?

If you’re mechanically inclined, replacing the engine on your lawn mower yourself can save you a substantial amount of money. However, it’s important to assess your skills and the complexity of the job before embarking on this endeavor.

Here’s a breakdown of the steps involved in DIY engine replacement:

  1. Research and Gather Supplies: Find the right replacement engine for your mower model and gather all the necessary tools and parts, including oil, air filters, and spark plugs.
  2. Disassemble the Old Engine: Carefully remove the old engine from the mower, noting the position and connections of all components.
  3. Install the New Engine: Mount the new engine in place, ensuring all connections are secure.
  4. Reconnect Components: Connect the fuel lines, spark plug wires, and other necessary components.
  5. Test and Tune: Start the new engine, making any necessary adjustments to ensure proper operation.

Key Considerations for DIY Engine Replacement:

  • Difficulty Level: Some engines are easier to replace than others, and certain mower models have more intricate designs.
  • Safety: Take precautions while working with engines, including wearing protective gear and working in a well-ventilated area.
  • Technical Knowledge: Ensure you have the technical knowledge and skills required to complete the job safely and correctly.

Alternatives to Replacing the Engine

Before investing in a new engine, consider these alternatives:

  • Tune-Up: A simple tune-up, involving cleaning the carburetor, replacing the spark plug, and adjusting the engine’s air-fuel mixture, might resolve the problem.
  • Repair: If the issue is specific to a certain component, like the carburetor or ignition system, repair might be a more affordable solution.
  • Used Engine: You might find a used engine in good condition at a lower price than a new one. However, ensure the used engine is compatible with your mower model and is in good working order.


The cost of a lawn mower engine can vary significantly depending on the engine type, horsepower, features, and brand. You can find replacement engines for small walk-behind mowers starting around $100, while larger riding mower engines can cost upwards of $1,000. If you’re considering replacing the engine, assess your mechanical skills, research the process thoroughly, and factor in the costs of parts and tools. Remember, alternatives like a tune-up or repair might be more cost-effective options in some cases. By understanding the factors that influence the cost of lawn mower engines, you can make informed decisions about maintaining or replacing your mower.


What are the different types of lawnmower engines?

There are two main types of lawnmower engines: gasoline and electric. Gasoline engines are more powerful and can handle larger lawns, but they also require more maintenance and produce emissions. Electric engines are more environmentally friendly and quieter, but they have less power and require a power cord. There are also cordless electric models that run on rechargeable batteries, offering a good balance of power and convenience.

Ultimately, the best type of lawnmower engine for you depends on your individual needs and preferences. Consider the size of your lawn, your budget, and your level of comfort with maintenance.

How much do lawnmower engines cost?

The cost of a lawnmower engine can vary widely depending on the type, brand, and horsepower. Gasoline engines can range from around $100 to $500, while electric engines can cost anywhere from $50 to $200. The price also depends on whether you are buying a new or used engine. Used engines can be a more affordable option, but they may not be as reliable as new engines.

It’s essential to factor in the cost of maintenance and fuel when considering the overall cost of ownership. Gasoline engines require regular oil changes and spark plug replacements, while electric engines require less maintenance.

How much horsepower do I need?

The amount of horsepower you need for your lawnmower engine depends on the size of your lawn and the type of grass you have. Smaller lawns and thinner grass can be handled by lower horsepower engines, while larger lawns and thicker grass will require more powerful engines.

A good rule of thumb is to choose an engine with at least 1 horsepower for every 1,000 square feet of lawn. For example, a 5,000 square foot lawn would require a 5 horsepower engine. If you have a particularly hilly or challenging lawn, you may want to consider an engine with more horsepower.

Where can I buy a lawnmower engine?

You can find lawnmower engines at a variety of retailers, including home improvement stores, hardware stores, and online retailers. Some specialty lawn equipment stores may also carry a wider selection of engines. If you are looking for a used engine, you can check online marketplaces or local classifieds.

When purchasing an engine, be sure to choose a reputable retailer with a good return policy. It’s also a good idea to read reviews from other customers before making a purchase.

How do I install a lawnmower engine?

Installing a lawnmower engine can be a fairly straightforward process, but it’s essential to have the right tools and knowledge. First, disconnect the spark plug wire and remove the old engine. Then, install the new engine and reconnect the spark plug wire. Be sure to follow the manufacturer’s instructions carefully.

If you’re not comfortable with the installation process, it’s always best to consult a professional mechanic. They can ensure the engine is properly installed and adjusted, preventing potential damage or accidents.

How do I maintain a lawnmower engine?

Maintaining your lawnmower engine will help to prolong its lifespan and ensure it runs smoothly. This includes regular oil changes, spark plug replacements, and air filter cleaning. You should also check the engine for any leaks or damage and make sure the blades are sharp.

The frequency of these maintenance tasks will vary depending on the type of engine and how often you use it. For gasoline engines, it’s recommended to change the oil every 25 hours of use or every season, whichever comes first. Check your owner’s manual for specific maintenance recommendations.

What are some common lawnmower engine problems?

Common lawnmower engine problems include:

  • Difficulty starting: This could be due to a dead battery, a clogged carburetor, or a fouled spark plug.
  • Loss of power: This could be caused by a dirty air filter, a clogged fuel filter, or a worn spark plug.
  • Excessive smoking: This could be a sign of worn engine parts, a leaking valve seal, or a damaged piston ring.

If you’re experiencing any of these problems, it’s best to consult a professional mechanic for diagnosis and repair. They can identify the issue and recommend the best course of action.

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