How to Build a Racing Lawn Mower: The Ultimate Guide to Constructing a Lawnmower for Shredding

Why build a racing lawn mower?

1. Speed up lawn mowing

Building a racing lawn mower can drastically speed up lawn mowing by allowing mowers to reach far faster speeds than what can be achieved with a garden-variety lawn mower. Racing mowers have been modified by their racers to include engines specifically built to reach high speeds, often with the help of a small engine repair shop. For example, in 2010, driver Bobby Cleveland was able to break the world record for the fastest lawn mower with a speed of 96.529 mph. In 2021, Antony Edwards was even able to reach a speed of 143.193 mph with his lawn mower, “Mowabusa”. This is much faster than the speeds of 6 or 7 mph that can be reached with a typical lawn mower. By building a racing lawn mower, the task of mowing the lawn can be accomplished much more quickly.

2. Improved Control and Stability

Building a racing lawn mower with a direct steering system will improve control and stability. By replacing the stock steering components with high-quality bearings, and securing nuts and bolts with nylock nuts and loctite, you will be able to reduce slop in the steering and increase responsiveness. Additionally, adjusting the camber of the right front wheel and setting the toe-out to 1/8″ on each side will help to make the mower more stable and easier to control. All of these improvements will ultimately result in better control and stability when racing.

3. Customized to the Driver’s Needs

Building a racing lawn mower can be customized to the driver’s needs by making the necessary modifications to the powertrain and chassis. Weight distribution, suspension, throttle and brake controls can all be tailored to the driver’s preferences, allowing for a smoother and more efficient ride. For example, lowering the mower’s center of gravity allows for better maneuverability, while wider tires with higher pressures can provide greater grip and stability. Additionally, the use of a hand throttle attached to the steering wheel can help the driver to more finely control the mower’s speed and acceleration. Ultimately, customizing a racing lawn mower to the driver’s preferences can provide a competitive edge and make it more enjoyable to drive.

4. Fun and Competitive Sport

What makes building a racing lawn mower a fun and competitive sport? Argumentation.

Lawn mower racing is a sport that is enjoyed by people of all ages and backgrounds, including children and retirees. It requires skill and knowledge to build a competitive lawn mower, making it a challenging yet rewarding experience. The Troyers, a family in Twelve Mile with six members who race annually, demonstrate that anyone can join the sport. With the help of the Troyers and other racers, anyone can learn the necessary skills to get involved.

The sport also allows for a lot of personalization and creativity. Racers create their own mowers with unique modifications that make them faster, allowing for an individualized racing experience. The technical know-how behind building a competitive mower is an important part of the sport, as racers can use data and analysis to optimize their mowers’ performance.

Aside from the competitive aspect, lawn mower racing also offers a great sense of community. Racers help each other out, sharing tips and advice to ensure that everyone is ready to race. The Troyers even lend a hand by helping to build and adjust mowers for other racers. Furthermore, the sport is characterized by a fun and light-hearted atmosphere, as racers joke around with each other and enjoy the camaraderie.

Overall, lawn mower racing is an exciting and enjoyable sport that encourages participation from a diverse range of people. It is a unique and thrilling experience, as racers can build their own mowers, compete in a competitive environment, and enjoy the sense of community that the sport offers.

5. Ability to Customize the Machine

The ability to customize a racing lawn mower offers several benefits when it comes to building a racing lawn mower. By customizing the mower, a racer can maximize the potential of the machine by improving its powertrain, chassis, weight distribution, and overall safety.

In terms of powertrain, modifications can be made to the transaxles to increase output speed and aftermarket filters and exhausts can be used to increase power. Additionally, the installation of centrifugal clutches, chain drives, and live axles can help with the mower’s performance.

Chassis modifications can be made to the mower to increase its strength and improve the center of gravity. This can be done by altering the wheelbase, welding the front suspension, and changing the width of the machine.

Weight distribution is also an important factor when it comes to building a racing mower. By lowering the center of gravity, the racer can improve the handling of the mower and make it easier to control. Additionally, the type of tires and the tire pressure can be regulated to provide more absorption of bumps.

Finally, the racer can also improve the overall safety of the mower by securing critical fasteners and adding a throttle close system and ignition kill switch. This can help to prevent any accidents while out on the track.

Overall, customizing a racing lawn mower offers numerous benefits when it comes to building a competitive racing mower. By making the right modifications, a racer can ensure that their mower is performing at its highest potential.

6. Save Money on Fuel and Maintenance

Building a racing lawn mower can save money on fuel and maintenance due to its lightweight construction and efficient engine. The engine is designed to be powerful enough to reach speeds of up to 50mph, yet still remain fuel efficient. Furthermore, the lawn mower’s chain and sprockets are designed to last longer than stock parts and require less frequent replacement, further reducing maintenance costs. As these parts are lighter and more durable than their stock counterparts, they are also less susceptible to wear and tear, further reducing the need for costly repairs.

7. Exercise and Physical Activity

The benefits of building a racing lawn mower are numerous, from the sheer thrill of driving one at high speeds to the pride that comes from constructing a powerful piece of machinery from scratch. Racing lawn mowers are a great way to get involved in a sport that can be both exhilarating and cost-effective. Not only is it a safe and enjoyable activity for all ages, but it can also provide a unique sense of accomplishment to anyone who takes the time to build their own machine. Additionally, lawn mower racing allows participants to hone their driving skills, as well as their problem-solving and engineering abilities, while also providing a chance to build relationships with fellow racers. Finally, the sport has seen an increase in popularity over the past few years, with events taking place all over the world, making this a great way to make new friends and join a larger racing community.

8. Increased Focus and Concentration

Building a racing lawn mower can be an excellent way to increase focus and concentration. This is because it requires careful planning and execution and can be an enjoyable challenge that helps develop problem solving skills. It requires attention to detail and accuracy in the construction of the mower, and it also requires the user to understand and follow safety protocols like wearing protective equipment for their own safety and others. Once the mower is built, the user must also take into account factors such as the terrain, the speed of the mower, and the steering system in order to navigate the race course successfully. All of this requires concentration and focus, which can help improve mental sharpness and alertness. Therefore, building a racing lawn mower can be a great way to increase focus and concentration.

9. Improved Hand-Eye Coordination

Building a racing lawn mower can greatly improve hand-eye coordination by providing hands-on experience in assembling and operating the mower. Through assembling the mower using nuts and bolts, connecting the steering wheel to the front wheels, and installing higher quality bearings, the user will gain an understanding and appreciation of the mechanics and components of the mower. With the use of proper safety equipment and understanding of the flag rules of the racing series, the driver will have to practice precision and accuracy in driving the mower in order to successfully navigate the track and win races. Therefore, the experience gained in building and driving a racing lawn mower will provide the user with a greater level of hand-eye coordination.

10. Possibility to Win Prizes and Recognition

Building a racing lawn mower can help win prizes and recognition by providing the opportunity to take part in a world-class lawn mower racing competition. These competitions give the opportunity to demonstrate skills and race against other competitors. Furthermore, by taking the lawn mower’s engine and converting it into a Go Kart, participants can race in a variety of different competitions with different levels of difficulty. By participating in these competitions, participants can gain recognition and potentially even win prizes for their accomplishments.

What to consider when buying parts for your racing lawn mower

1. Racing Lawn Mower Parts: Quality and durability

When looking to purchase parts for a racing lawn mower, it is important to understand the quality and durability of the parts. Acceleration, stability and handling are three qualities that are most focused on by those participating in the sport. Thus, it is essential to choose a gas engine mower that is powerful enough to compete in the race. In terms of stability, choosing a mower that is able to stay in control during turns and sudden movements is ideal. For handling, a slower mower is recommended for those who are new to the sport.

In terms of durability, it is important to find a replacement engine for the mower that is made from strong material such as billet aluminum. This can help reduce the wear and tear that the mower will face during a race. Additionally, all blades must be removed from the mower for safety reasons. This can be done professionally or by the racer themselves if they are tech-savvy and into DIY projects.

Finally, it is important to consider the unique designs and external and internal structures of the lawnmower when buying parts for a racing mower. This can help ensure that the parts purchased are compatible with the mower and will be able to withstand the rigours of a race.

2. Racing Lawn Mower Parts: Cost and budget

Racing lawn mower parts can be quite expensive, but there are ways to purchase them at a more affordable price. The cost of racing lawn mower parts depends on the quality of the parts and the type of lawn mower you are using. Generally, purchasing parts from scrap yards and garage sales can be a cheaper option, as well as checking eBay and other auction sites. Buying used parts can also save costs, as well as asking friends and family for old lawn mowers they are no longer using.

If you are tech-savvy and into DIY projects, you can also save on costs by doing the upgrades on your own, instead of getting the task done professionally. The list of parts needed includes an engine, centrifugal clutch, sprockets, transmission, steering wheels, axles and hangers, electrical components, wheel systems, a gas lever, and some other high endurance engine upgrades. Most modern models of lawn mowers should have sufficient replacement parts available, both in hardware stores and online.

Finally, for those who are new to the sport, purchasing a lawn mower that is a bit slower is recommended, as racing with a fast lawn mower can be challenging to handle and dangerous. All in all, the cost of racing lawn mower parts can vary widely, and with a bit of research and a DIY approach, one can find the parts they need at an affordable price.

3. Racing Lawn Mower Parts: Selection and variety

Racing lawn mower parts are available in a variety of options, each tailored to improve the performance of the mower.

The most important part of any racing mower is the engine, which should be a gas powered engine to maximize the power of the mower. Centrifugal clutches, sprockets, and transmissions are also essential components, as they are integral to the mower’s acceleration and stability. Additionally, steering wheels, axles, hangers, electrical components, and wheel systems are necessary components to ensure the mower handles correctly. Finally, a gas lever and other engine upgrades are necessary to ensure the mower can handle the intensity of the race.

These parts are available in both stock and custom configurations, allowing for racers to tailor the mower to their specific needs. Furthermore, many parts are available in hardware stores and online, making it easier to find what is needed.

4. Racing Lawn Mower Parts: Size and scale

When choosing parts for a racing lawn mower, size and scale should be taken into account to ensure a safe and successful race. The larger and more powerful the engine is, the better the performance and the faster the mower will be, but this also increases the risk of dangerous speeds and the need for extra stability. Smaller engines tend to be less powerful, but can provide better maneuverability and control.

When it comes to weight, the heavier the mower is, the more stability it will have, but this also means it will be harder to maneuver and turn. Lighter mowers offer more agility, but at the cost of stability.

Finally, the cost of the build and racing should be taken into account when choosing parts. Building a racing mower from scratch can be expensive, so it’s best to start with an affordable mower and upgrade it with specific parts. Racing entry fees can also add up quickly, so it’s important to keep costs in mind when choosing a mower.

5. Racing Lawn Mower Parts: Weight and balance

Weight and balance considerations are extremely important when buying parts for a racing lawn mower. The lower the weight, the more acceleration and stability the mower will have. To achieve this, lightweight parts such as billet aluminum flywheels and rods, an aftermarket racing carburetor, and a high-quality billet aluminum camshaft should be used. Additionally, the balance of the mower should be taken into account. A good balance means that the mower has an even distribution of weight, allowing it to stay steady and maneuver swiftly. To ensure proper balance, purchasing adjustable axle hangers, spindles, and chain kits can help. Finally, high-endurance engine components such as pistons, cylinders, and seals should be used to ensure that the engine can handle the extra strain of racing.

6. Racing Lawn Mower Parts: Strength and strength

When building a racing lawn mower, one needs to take into consideration the strength and durability of the parts. It is important to choose parts that are powerful enough to handle the stress of racing, such as a gas engine mower to bring up the mower’s power and high-quality parts to build a great racing mower engine. Acceleration, stability, and handling are also very important in order to ensure a successful race. To achieve this, parts such as the governor, carburetor, pistons and rods, flywheel, and camshaft must be of the highest quality. Additionally, reinforcing the frame of the mower will protect it against fatigue-related cracks and damage. All in all, when building a racing lawn mower, it is essential to choose parts that are both strong and durable.

7. Racing Lawn Mower Parts: Fit and finish

When it comes to buying parts for a racing lawn mower, there are several considerations for fit and finish to take into account. When it comes to the engine, you’ll want to make sure that it is powerful enough to provide the speed and acceleration needed for the track. You should also make sure that it fits in the mower properly.

Additionally, when it comes to the brake system and centrifugal clutch, you’ll want to make sure that they are compatible with the other components and that they can provide adequate stopping and shifting performance. The same goes for the transmission, steering wheel, and fuel tank. It’s important to make sure that all of these components are compatible with each other and fit together perfectly.

Finally, when it comes to internal and external components, be sure to look for parts that are designed to be durable and can withstand the rigors of racing. For example, when it comes to the wheel systems, you’ll want to make sure that they are strong enough to handle racing conditions and won’t break down.

Overall, when it comes to fit and finish, you’ll want to make sure that all of the parts you purchase fit together properly, are designed to last, and provide the performance needed for racing.

8. Racing Lawn Mower Parts: Design and style

When it comes to designing parts for a racing lawn mower, there are a few key design and style considerations to think about. First, the power and weight stats are important to consider. Most rider mowers have an average horsepower range of 10-50 and a typical race weight range of 450-600 lbs. This will determine the size and type of engine, transmission, wheels, and brakes that you need to get the best performance out of your mower. Additionally, it is important to think about the build cost, build effort, racing cost, and transportation and support equipment. All of these elements need to be taken into consideration to ensure the mower is safe, efficient, and cost-effective. Furthermore, the knowledge level of the builder is important. There are certain knowledge requirements to ensure the parts are installed correctly and that the mower meets regulations for the specific racing event. Finally, it is important to think about the design challenges, design resources, construction challenges, and build costs. These elements will help determine the overall cost and effort for the build.

9. Racing Lawn Mower Parts: Smoothness and response

When it comes to buying parts for a racing lawn mower, there are several factors to consider. Firstly, you need to think about acceleration. Gas engine mowers have higher power than electric mowers, so they are the best option for faster acceleration. Secondly, you need to think about stability. No matter the terrain, you need a lawn mower that won’t be thrown off balance during maneuvers. Thirdly, handling is important. If it’s your first time racing, it is better to choose a mower that is slower and easier to handle.

It is also essential to remove the blades of the lawnmower for safety reasons. To upgrade your lawnmower for racing, you will need to purchase a variety of replacement parts, such as an engine, centrifugal clutch, sprockets, transmission, steering wheels, axles, hangers, electrical components, wheel systems, and a gas lever. You can either purchase brand new parts or find them in second-hand stores or online.

Lastly, you need to have the right tools and parts. It is possible to reuse the old lawn mower, such as the engine, brake system, and steering wheel, to build the racing lawn mower. You will also need additional tools, such as a centrifugal clutch, engine set up component, tires, and sealant. With the right tools and parts, you can successfully build your racing lawn mower.

10. Racing Lawn Mower Parts: Speed and acceleration

When evaluating racing lawn mower parts for speed and acceleration, there are several factors to consider. Acceleration is paramount, so having a gas engine mower is usually the best bet. Stability is also key, so the mower should be able to handle sudden movements and turns without going out of control. Lastly, handling is important; it is better to race with a mower that is not too fast, because it can be dangerous and difficult to handle on uneven terrain.

When comparing, gas engine mowers are typically the best choice for acceleration, as they already have a lot of power compared to electric mowers. When it comes to stability, one must consider the terrain and make sure their mower can handle the bumps and turns. Finally, when it comes to handling, it is usually safer to start with a mower that is slower and easier to control.

On the other hand, when it comes to speed, modified-class racers can build their mowers to go as fast as possible, with some even reaching up to 143 mph. These mowers are often constructed from scratch, with racers utilizing a variety of parts and modifications to get the highest speed possible. Furthermore, some racers even enjoy the challenge of transforming an old, junky lawn mower into a speed machine.

11. Racing Lawn Mower Parts: Braking and stability

When racing lawn mowers, you need the right parts and components to ensure braking and stability. This includes a steering wheel, brakes, a transmission (right angle gearbox), sprockets, chain, rear axle and axle hangers, front axle and spindles, wheels, tires, and hubs, centrifugal clutch, high endurance engine component, gas lever, and electrical components. It is also important to have a puke tank installed which is a tank to hold your engine and prevent it from leaking oil on the race track. Additionally, a seat should be installed for safety and comfort, and finally large wheels with deep treads should be selected to help with off-road racing.

12. Racing Lawn Mower Parts: Steering and turning

What parts are needed for steering and turning a racing lawn mower? [Expanded list]:

Steering Wheel, Rear Axle and Axle Hangers, Gas Lever, Brake System, Wheels, Tires, and Hubs, Centrifugal Clutch, Front Axle and Spindles, Chain, Transmission (Right Angle Gearbox), Sprockets, Electrical Components, High Endurance Engine Component.

13. Racing Lawn Mower Parts: Gears and transmission

There are several types of gears and transmissions available for racing lawn mowers, including the centrifugal clutch, right angle gear box, and chain. The centrifugal clutch is a device that allows the engine to start and stop quickly, and is necessary for racing lawn mowers. The right angle gear box is a transmission that allows the engine to rotate in a more efficient manner, increasing the speed of the lawn mower. The chain is a transmission that connects the engine to the other components of the lawn mower, allowing for power transfer between them. Finally, the sprockets are used to transfer power from one component to another, and a high endurance engine component may be necessary for racing lawn mowers that are being used in long races.

14. Racing Lawn Mower Parts: Brake system and brakes

When setting up a racing lawn mower, it is important to consider the brake system and brakes. Hydraulic brakes are the better option for lawn mower racing, as they are easier to install and provide better performance than mechanical brakes. Hydraulic brakes require a source of pressurized fluid to work, while mechanical brakes use friction and leverage to stop the mower. Additionally, hydraulic brakes can provide more stopping power, allowing you to corner faster and with more control. Lastly, hydraulic brakes are much more reliable than mechanical brakes, as they are more resistant to heat and wear.

15. Racing Lawn Mower Parts: Linkage and damper

Linkage and damper parts play an important role in racing lawn mowers. The linkage is used to ensure that the throttle is operated in a proper and consistent manner, while the damper absorbs shocks from bumps and uneven terrain.

When selecting linkage and damper parts for a racing lawn mower, it is important to consider the material used and the design of the parts. Many linkage and damper parts are constructed using lightweight materials such as aluminum or carbon fiber, which help reduce the overall weight of the lawn mower. Additionally, the design of the parts must be carefully considered as they must be able to withstand the high speeds of racing.

In contrast, when selecting linkage and damper parts for a regular lawn mower, the considerations are different. Regular lawn mowers do not have to endure the same speeds as racing lawn mowers, so lighter materials and simpler designs can be used. Additionally, regular lawn mowers do not have to be as aerodynamic as racing lawn mowers, so the parts can be designed with more bulky shapes.

16. Racing Lawn Mower Parts: Axle and axle brackets

Axles and axle brackets are essential components of a racing lawn mower. They are essentially the frame of the vehicle, providing the structure to hold all the other parts in place. The axle connects the wheels and is usually made of steel, while the axle brackets are the metal pieces that attach the axle to the frame of the mower. They are essential for providing stability and strength to the entire mower, as well as providing a platform for the tires and wheels to move freely.

When selecting axles and axle brackets for a racing lawn mower, it is important to consider their strength and durability. The axles and axle brackets must be strong enough to withstand the demands of racing, and should be able to handle the high torque and vibrations that is common in racing. Additionally, the axles and brackets should be corrosion-resistant, as they will be exposed to the elements, and should be lightweight to reduce the overall weight of the mower.

Other components that need to be considered when selecting axles and axle brackets are the wheel size and type, as these will impact the overall performance of the mower. Additionally, the tires and wheels need to be compatible with the axle and axle bracket to ensure a safe and secure fit. Lastly, the quality of the axles and axle brackets is paramount. Cheap and low-quality components can be dangerous and lead to catastrophic failure of the mower, so be sure to invest in quality components.

17. Racing Lawn Mower Parts: Safety and security

When buying parts for a racing lawn mower, there are a few safety and security considerations to keep in mind. Firstly, make sure to double-check the parts for compatibility with your lawn mower. Secondly, wear protective gear such as gloves and safety glasses when working with any tools and parts. Thirdly, pay close attention to the quality of the parts and their durability. Fourthly, always take the necessary precautions when working with gasoline or other flammable liquids. Fifthly, make sure to install all of the parts correctly, to avoid any malfunction or damage. Sixthly, check the racing laws in your area before engaging in any races. Finally, if possible, have a professional mechanic do the installation and repairs on your racing lawn mower.

18. Racing Lawn Mower Parts: Engine and carburetor

When buying parts for a racing lawn mower, it is important to consider the engine and carburetor components needed for the build. The most important components for the engine include a governor, carburetor, pistons and rods, flywheel, and camshaft. The flywheel should be as lightweight as possible, such as a milled aluminum replacement, while the pistons and rods should be of a billet aluminum build. The camshaft should be a racing camshaft that has higher ramp speeds and increased lift. Lastly, the carburetor should be an off-the-shelf racing carburetor that will improve airflow. In addition to engine components, other tools and parts needed for the build include a brake system, centrifugal clutch, steering wheel, wheels, chain, transmission, fuel tank, tire sealant, and gloves.

19. Racing Lawn Mower Parts: Piston and rod

Piston and rods are typically used to control the engine’s power output and speed. The piston is the cylindrical piece of metal that moves up and down in the cylinder and is connected to the crankshaft via a connecting rod. The movement of the piston creates the combustion that powers the engine. The rods, which are also made of metal, are used to connect the piston to the crankshaft and are designed to withstand the force of the combustion. This allows the piston to move up and down and control the speed and power of the motor, ultimately determining the performance of the racing lawn mower.

20. Racing Lawn Mower Parts: Hanger and welds

When it comes to building a racing lawn mower, the most important components are the engine, steering wheel, rear axle and axle hangers, gas lever, brake system, wheels, tires, and hubs, centrifugal clutch, front axle and spindles, chain, transmission (right angle gearbox), sprockets, electrical components and high endurance engine component. It is also important to consider the engine power, the type of brakes and the transmission when purchasing parts for a racing lawn mower. Additionally, reinforcing the frame and installing a puke tank to prevent oil spills is essential for racing. Finally, for a complete racing lawn mower, a new paint job will make the mower stand out from the rest.

How to build a racing lawn mower from scratch

Step 1: Choose a race group

When it comes to participating in lawnmower races, it’s important to understand the different race groups available and how to choose the one that’s right for you. The American Racing Mower Association (ARMA) has four groups, Group 1, Group 2, Group 3, and Group 4. Group 1 is for standard mowers, Group 2 is for modified mowers, Group 3 is for modified mowers that are faster than Group 2, and Group 4 is for high-performance mowers. Each group has different requirements for the mower, including modifications, safety gear, and other requirements. To choose the race group that’s right for you, it’s important to consider the type of mower you have and your racing ability. Once you’ve determined the best group for you, you’ll need to get your mower homologated and equipped with the required safety gear before you can start racing.

Step 2: Frame reinforcement

Frame reinforcement is the process of strengthening a frame to prepare it for use in a racing lawn mower. By reinforcing the frame, the mower can better handle the rigors of racing, and the frame will be able to withstand the high speeds and rough terrain that is often associated with racing. This can be done by using reinforcement materials such as square tubing or diamond plate to add support to the frame and make it stronger. Additionally, a right angle gearbox and centrifugal clutch can also be used to increase the strength and reliability of the mower. Frame reinforcement is crucial for a racing lawn mower as it will help to ensure that the mower is able to properly handle the challenges of racing, and that the frame is not prone to cracking or breaking due to fatigue.

Step 3: Steering system

The steering system for building a racing lawn mower from scratch involves setting up a direct steering system, connecting the steering wheel with the front wheels, and installing a solid connection between the steering wheel and the front wheels. You can purchase a pre-built front axle from a company like Acme Mowersports, which will already have the proper caster and degree of inclination set. Then you need to install the steering shaft, running along the front of the frame, and attach a removable lever to connect the steering wheel pitman arm. You may also need to adjust the heim joints to adjust the steering sensitivity, and determine the angle of the wheels. Finally, you will need to install stops to prevent the wheels from turning too far.

Step 4: Install the transmission or the RAGB

  1. Determine the necessary gearing ratio for the RAGB. The RAGB is a 2:1 ratio, meaning that two turns go in and one comes out of the output shaft. Calculate the gear setup using the number of teeth on the centrifugal clutch, input on the RAGB, output from the RAGB, and rear axle sprocket.

  2. Attach the RAGB to the frame using two cross members welded in the frame. Ensure that the RAGB is far enough of the ground, yet not too far up as to protrude above the diamond plate covering it.

  3. Install chain tensioners. The chain should be somewhat taut, but not tight. All chains will loosen and ‘stretch’ with use. Install a skateboard wheel that slides up and down in a 1×1 piece of steel with a slot milled along its length to create tension.

  4. Install the simulated mower deck. This should be made out of steel square tubing welded into “C”s with wire mesh tacked on top. Weld the simulated mower deck directly to the bottom of the frame.

  5. Install the battery. The battery should be placed behind the engine. To do this, weld two angle iron pieces pointing upwards to form a bracket in which the battery sits.

  6. Install diamond plate floor plates and dash. Cut the diamond plate to size and screw on with self-drilling screws so that both panels can be removed for servicing the RAGB and transmission.

  7. Install the electric panel. Screw and bolt all of the electrical components, such as the starter button, starter solenoid, and tether switch, to the dash panel.

  8. Fix the internal components. Ensure that all components are installed correctly and working as expected.

Step 5: The brake system

Building a racing lawn mower brake system is a fairly straightforward process that can be done in a few easy steps.

  1. Choose a brake system: You can choose from mechanical or hydraulic brake systems. Hydraulic brakes are generally better and easier to install, as you can route the brake lines to wherever you want them. An example of a hydraulic brake system that you can use is an MCP go cart brake kit, which runs at around $150 including the master cylinder, rotor, rotor hub, caliper, and brake line. You can also use motorbike brakes if you have any lying around.

  2. Install the caliper: Drill two holes through the frame where the bolts holding the caliper would go through. It may be necessary to create a caliper mounting bracket. When done, bolt on the caliper and make sure it is aligned properly with the rotor. The rotor and other components on the axle are adjustable and slide back and forth on a keyway milled into the axle shaft. Once adjusted, you lock them down with set screws.

  3. Install the master cylinder: Bolt the master cylinder through the frame. The three holes in the aluminum piece is the connection for the brake pedal connecting rod, which is made out of 1/4″ steel rod bent @ 90 degrees. The other end of the rod connects to the pedal, which is made out of scrap steel and a short length of 1×1 square tubing with a hole drilled through the bottom in which to run a bolt through the frame. A nylock nut on the other side allows it to stay in place yet swivel back and forth.

  4. Bleed the brakes: Before using the brakes, make sure to bleed them to ensure they are working properly.

Once you’ve followed the steps above, your racing lawn mower brake system should be good to go. Enjoy racing!

Step 6: Install floor plates, mower deck, and battery

Step 1: Install the floor plates

To install the floor plates, first cut them to the right size. Then, use self-drilling screws to attach the floor plates to the mower.

Step 2: Install the mower deck

To install the mower deck, use a steel square tubing welded into “C”s with wire mesh tacked on top. Then, weld the deck directly to the bottom of the frame.

Step 3: Install the battery

The battery should be mounted behind the engine, so weld two angle iron pieces pointing upwards to form a bracket. Then place the battery inside the bracket. Put a piece of rubber between the battery and the diamond plate to avoid abrasion.

Step 4: Secure the electrical components

Secure the starter button, starter solenoid, and tether switch to the dash panel. Make sure all the electrical components are screwed and bolted.

Step 5: Install the engine

Install the engine with 12 horsepower, which is suitable for racing mowers. Attach the engine to the battery and the chain to the wheels.

Step 6: Revamp the look of the mower

Give the new race machine a good scrub and then paint it with eye-catching colors. Once the paint has dried, it’s time for a test run.

Step 7: Puke tank, engine mounting, and other items

To build a lawn mower for racing, you will need the following items:

Puke Tank: ABS plastic pipe, brass hose fittings, PVC for the breather, engine mounting pan, keyhole shaped slots for engine, spring-loaded tensioner, channeled nylon idle pulley, chain, and a bolt welded to the underside of the engine pan.

Engine: 12 horsepower engine, batteries, electrical components, high endurance engine components.

Steering System: Steering wheel, rear axle, axle hangers, gas lever, brake system, wheels and tires, hubs.

Transmission: Centrifugal clutch, front axle and spindles, chain, right angle gearbox, sprockets.

Additional Components: Seat with low sides and padding, paint job.

Step 8: Engine modifications and installation

Building a racing lawn mower from scratch requires several modifications and installations to the engine. The first step is to get a Briggs 14.5 OHV engine, as it has many similarities to the 12.5 flathead. The next step is to scavenge a magnesium piston and billet rod, and replace the rod bearings if necessary. Additionally, an ARC billet chrome molybdenum billet crank should be purchased to replace the heavy cast iron counterweights and offer lightweight brass counterweights. New valves and valve keepers should be purchased, as the old-style keepers can come loose during racing and cause damage to the head.

An ARC billet flywheel with a removable steel hub should be purchased, as the old flywheel is likely damaged from slipping numerous times on the crank. The flywheel must be lapped for a tight fit, and then should be torqued down with an air impact wrench. Finally, a high-torque starter should be installed, making sure that the teeth of the starter are not too tightly meshed with the ring gear of the flywheel.

The last step is to port and polish the engine. This involves shaving down any sharp edges in the intake and exhaust ports, and polishing them with a stone and polishing compound. This will ensure smoother airflow in and out of the engine. Once these steps are completed, the racing lawn mower is ready to hit the track.

Step 9: Install a good transmission on your lawnmower

Step-by-Step Instructions for Installing a Good Transmission on a Racing Lawn Mower:

  1. Begin by selecting a transmission that is designed for racing lawnmower frames and is far enough from the ground but still fits comfortably within the frame of your lawnmower.

  2. Weld the mower deck to the mainframe of the mower, ensuring that it is tight enough.

  3. Install the batteries underneath the deck and complete the electrical connection.

  4. Install the puke tank that will hold the engine and prevent oil spills.

  5. Install the engine, preferably with 12 horsepower.

  6. Attach the engine to the battery.

  7. Attach a chain to the wheels for a smoother drive.

  8. Give the mower a new paint job with eye-catching colors.

  9. Install the hydraulic brakes, as they are better suited for the racing mower.

  10. Attach the seat to sit on, preferably a school seat without legs or old car foam wrapped seat for comfort.

  11. Test run the mower and make sure all components are functioning properly.

Step 10: Replace the stock steering components of your lawnmower

Step 1: Replace the stock steering components of your lawnmower with a pre-built axle from a sports mower specialist, such as Acme mowersports ( This will provide the juice that most models of racing lawnmowers just do not have.

Step 2: Install a direct steering system, which is a solid connection between the steering wheel and the front wheels.

Step 3: Install a steering shaft running along the front of the frame. This should have a removable lever at the top to attach the piece of linkage coming from the steering wheel.

Step 4: Install heim joints, which are screw-on ball bearing pieces on the ends of the rods. These will be used to adjust the amount of right and left turn in the wheels.

Step 5: Determine the angle of the wheels. Generally, it is better to have the left wheel turn in more than the right. I usually have the left wheel turn in @ 10:00 and the right at 2:00.

Step 6: Install “stops” which are basically welded on rods or bolts to prevent the wheels from turning too far. If they turn too far, the steering wheel will turn completely over, thus reversing your steering.

Step 11: Inspect your lawnmower; make sure it fits the rules correctly

Racing lawnmowers requires careful preparation and adherence to the rules and regulations specified by the racing association. To properly prepare your lawnmower, you must first obtain a membership from the British Lawn Mower Racing Association (BLMRA), Scottish Lawn Mower Racing Association (SLMRA) or United States Lawn Mower Racing Association (USLMRA) depending on your location. After you become a member, you must choose your race group and select a suitable lawnmower, modified the engine, install a puke tank, suitable brakes, a reinforced frame, a suitable deck, a good transmission and replace the stock steering components. Once all the modifications are made, you must inspect the lawnmower to make sure it adheres to the rules and regulations set by the racing association. The last step is to put on the Personal Protection Equipment (PPE) and to follow the rules of the race. Lawnmower races in the USA typically take place from April to October.

Step 12: Updates for 2011 – Total overhaul

In 2011, I decided it was time for a total overhaul of my racing lawn mower. The first step was to extend the frame by six inches, bringing it up to the maximum length of 42″ permitted for Mod-X machines. Next, I replaced the old 12.5 Briggs Flatty engine with a 14.5 Briggs Overhead Valve engine that was outfitted with a billet rod, billet ARC flywheel, High-torque starter, billet crank with built-in lightweight counterweights, a high performance cam, Higher strength valve springs and better valve keepers. Additionally, I had the rings filed to an absolute close tolerance in order to increase compression. The mower also got a new fully adjustable steering system that allowed me to adjust the caster and camber. This was important for improving the handling of the mower. Finally, I found a “donor mower” to provide new sheetmetal for the vehicle.

Safety is always a top priority when it comes to mower racing, so I made sure to equip the mower with the necessary safety features like real brakes (not the crappy ones the mower came with), a safety tether that cuts power if you fall off, and others. Additionally, it is important to wear the proper safety gear to protect oneself while racing, such as a DOT approved helmet, gloves, boots, long pants, and a neck collar or a neck brace. With all of the updates my mower was ready to take on the upcoming racing season!

Step 13: Building the new engine part 2

Step 14 : Polishing and porting the engine part 2

Step 1: Start by setting up a work area that is well-ventilated and able to contain the potentially harmful dust from polishing and porting. It is also recommended to wear protective gear, such as goggles and a mask, when doing this work.

Step 2: Mount a mill file in a vise, making sure that the file is straight up and down. Take a ring and slowly pull up on the ring with the end of the file until it is as level as possible.

Step 3: Take the ring and place it in the cylinder, then tamp it until it is level with the top of the piston. Using a feeler gauge, measure the gap and adjust the ring accordingly. Repeat this process until you reach the desired gap size.

Step 4: Using a Dremel tool, start to shave down and blend the edges of the intake and exhaust ports. Be sure to take your time and not rush through this part, as you do not want to damage the ports.

Step 5: Once the edges have been blended down, use polishing compound to give the ports a mirror polish. Keep in mind that this part can take a few hours, so be patient.

Step 6: Once the ports have been polished, reattach the head and the flywheel. Make sure that all the bolts are tightened correctly and that there are no leaks.

Step 7: The last step is to adjust the timing of the engine. This is best done with a timing light and should be done carefully to ensure that the engine is running correctly. With this done, the engine is ready to start up and run like a dream.


What parts are necessary to build a racing lawn mower?

What parts are necessary to build a racing lawn mower?

In order to build a racing lawn mower, you will need the following parts: an engine, engine set up components, a centrifugal clutch, a hydraulic brake system, a steering wheel, front and rear axles, a chain, a transmission, front and rear wheels, a fuel tank, electrical equipment, hand gloves, goggles, tire sealant, a billet flywheel, an aftermarket racing camshaft, and an off-the-shelf racing carburetor. Additionally, it is important to remove the blades of the lawnmower for safety reasons.

What type of engine is best for a racing lawn mower?

When it comes to racing lawn mowers, the most important item needed to participate is a great racing motor. The engine is the heart of the lawn mower and the type of engine chosen will determine the power and speed of the lawn mower. The best engine for a racing lawn mower will depend on the type of racing, but generally a flathead engine is not suitable for race conditions. The best option is to choose a gas engine mower for the higher levels of power. Billet aluminum is the preferred material for replacing the engine, flywheel, pistons and rods, camshaft, and carburetor. The lightweight aluminum will help reduce the weight of the engine and the increased lift of the camshaft will make the engine more powerful and faster. The improved airflow from the racing carburetor will also make the engine faster. Finally, stability is key, which is why it is important to make sure the mower is designed to handle sharp turns and sudden movements.

How can I modify a stock mower to race?

If you’ve ever wanted to turn your lawnmower into a high-speed racing machine, this guide can help you do it with a few simple modifications. Whether you’re looking to compete in national racing events or just to customize your mower for fun, this step-by-step guide will help you get started.

Step 1: Ensure safety is your top priority. Racing mowers are heavily modified to handle much greater speeds than the original mower was designed for, and many of these mowers go 50MPH or more. It is not a good idea to take a bone stock mower and make it go fast, as you can get hurt if you do so. Make sure to check out and adhere to the rules of your local chapter, and wear all appropriate safety gear such as a helmet, gloves, boots, and long pants.

Step 2: Choose your mower. Look for one that is small and light, as this will give you a better power-to-weight ratio. If you can find an older mower, like the late 60’s Grants mower, these are even better as they are usually lighter than their modern counterparts.

Step 3: Strip the mower down to the frame. This will let you see what is usable and how you can lay out the components. Make sure to keep the hood, as you will need this.

Step 4: Modify the frame. Reinforce the frame with steel tubing, as this will help it to better handle the increased speeds. Make sure to check rules and regulations for the racing event to make sure your mower is compliant.

Step 5: Modify the wheels. Replace the stock wheels with wider, thicker tires that can better handle the increased speeds. Make sure to check the rules and regulations for the racing event you will be participating in to make sure your wheels are compliant.

Step 6: Modify the steering. Upgrade the steering components to allow for better control. This can include increasing the size of the steering wheel, fitting a stronger steering box, and adding hydraulic steering.

Step 7: Modify the brakes. Fit racing brake discs and pads that can better handle the increased speeds. Make sure to check rules and regulations for the racing event you will be participating in to make sure your brakes are compliant.

Step 8: Modify the engine. Increase the power output of the engine and make sure all components are in good working order. Make sure to check rules and regulations for the racing event you will be participating in to make sure your engine is compliant.

Step 9: Fit a safety tether switch. Make sure your mower has an approved jet ski/snowmobile style safety tether switch so that if you fall off, the mower will shut down automatically to prevent further danger.

Step 10: Test your mower. Take your mower out and test it on a controlled course, such as a track. Make sure to follow the safety regulations and be aware of your surroundings, and don’t exceed the speed limits.

Step 11: Race! Finally, you can enter your mower into the race. Make sure to follow all regulations and stay safe, and have fun!

By following these steps, you can turn your lawnmower into a high-speed racing machine. So go ahead and get started on your racing mower build today!

How do I weld a racing mower chassis?

Step 1: Start by modifying the existing frame of the lawn mower. Add extra metal pieces with the existing frame to make it stronger and weld the additional metals with the main frame.

Step 2: The shape of the frame should be such that it is not too far away from the ground. 4 inches is the ideal distance.

Step 3: If you plan to use 1×1 square tubing for reinforcement, cut off about 6 inches from the rear end of the frame.

Step 4: Weld two lengths of square tubing along the top of the axle brackets to the front tubular frame. This is to put the transmission underneath and protect the rider from flying debris or potential chain failures.

Step 5: Install a right angle gear box or RAGB instead of the usual 3-5 speed gearbox. This will ensure higher speed applications and better reliability.

Step 6: Attach a centrifugal clutch to the frame. This will ensure the safe operations of the mower.

Step 7: Finally, clean up the frame with sandpaper flap discs to make it prepare it for painting. Use a primer and then paint the frame with black spray paint.

How do I build a brake system for my racing mower?

Step 1: Install the transmission with the mower.

Step 2: Set up the hydraulic brake system. Purchase a hydraulic brake system that is suitable for the racing mower and easy to install.

Step 3: Weld the mower deck to the frame.

Step 4: Install the puke tank. This tank is designed to hold the engine and prevent oil leakage on the race track.

Step 5: Install the seat. Most commonly used are school seats without legs, but you can use a car foam wrapped seat for more comfort.

Step 6: Install the engine. We recommend using a 12 horsepower (HP) Briggs and Stratton engine for the racing mower. Place the engine in an engine shroud.

Step 7: Connect the battery with the engine. Place the battery underneath the seat.

Step 8: Attach a chain between the engine and the rear wheel. This will help you drive the mower easily.

Step 9: Paint the mower. Choose a light and eye-catching color.

Step 10: Install the front wheel to give the mower the final look. Check all connections and internal components carefully.

And you’re done! Your racing mower is now ready to hit the track.

What type of transmission should I use for my racing mower?

When it comes to transmission for racing mowers, there are two main types to consider: mechanical and hydraulic. Mechanical transmissions are typically less expensive and easier to install, but they provide less power as compared to hydraulic transmissions. Hydraulic transmissions are more expensive and require more installation time and effort, but they do provide better power, control, and efficiency. When it comes to racing mowers, hydraulic transmissions are often seen as the better choice due to their increased performance. However, it is important to note that many transmission boxes are not designed for racing lawnmower frames, so you must install a transmission shaft that fits comfortably within the frame. Additionally, hydraulic brakes are more suitable when it comes to racing mowers, and they should be installed as well.

What safety features should I include in my racing mower?

When building a racing mower, it’s important to consider safety features to ensure that you and your mower are as safe as possible during competition. Here is a list of safety features to consider adding to your racing mower:

  1. Reinforce the frame of your mower to guard against fatigue-related damage.

  2. Use larger wheels with deep treads for better off-road traction.

  3. Install brakes that are capable of handling higher speeds, such as hydraulic brakes.

  4. Make sure the engine, battery, and electrical system are securely fastened to the frame.

  5. Choose a comfortable seat that has been covered with foam or other padding.

  6. Add a puke tank to contain any oil leaks from your engine.

  7. Make sure all of your modifications are securely fastened and in good working order.

  8. Wear proper safety gear such as a helmet, goggles, and gloves while operating the mower.

By following these tips, you’ll be well on your way to having a safe, competitive racing mower. Good luck!

What are the rules for racing mowers?

The rules for racing mowers are as follows:

Driver Eligibility:

  • Drivers must be members of the U.S. Lawn Mower Racing Association or must race as part of a sanctioned USLMRA Affiliated Club (AC).

  • Drivers must be 18 years of age. Drivers 8-17 years of age can race with parental permission.

  • All drivers must sign a release discharging the USLMRA from liability.

Mower Eligibility:

  • Events are open to all self-propelled rotary or reel style riding lawn mowers.

  • The mower must originally have been designed and sold commercially to mow lawns.

  • It must remain suitable for lawn cutting, apart from the modifications permitted in the Handbook.

Technical Inspection:

  • Every mower entered in any USLMRA event must be approved for competition by Technical Inspection.

  • Any mower may be re-inspected at any time by the Chief Steward or Chief Technical Inspector.

Mower Requirements:


  • Non-stock mowers must be equipped with an automatic throttle closing device.

  • All mowers must be equipped with an engine safety cut-off switch.

  • Mower brakes must be in good condition, operating on at least 2 wheels.

  • Fuel must be pump gas. The only additive allowed is STA-BIL Fuel Stabilizer.

Driver Safety Equipment:

  • Every driver must wear an automobile racing or motorcycle-type safety helmet.

  • Every driver shall wear long pants, a long-sleeved shirt, gloves and proper shoes on the track.

  • It is MANDATORY that all drivers wear an “approved for racing” neck support.

Rider Mower Classification:

  • Stock Class: As delivered from the factory with blades removed.

  • JP Class: Class for kids ages 10-15.

  • IMOW Class: (Int’l Mowers Of Weeds) Front engine, highly regulated.

  • Prepared Class: Prepared (modified) drive train, engine, etc.

  • FX Class: Major modifications allowed.


  • You must make sure that your lawnmower is homologated (inspected and approved to race).


  • The speeds vary by class. Stock classes may only go about 6 to 8 mph. The prepared (modified) classes have been known to go as fast as 85 mph.




  • There has been organized lawn mower racing in the U.S. and in England for more than 30 years.


  • To make your mower go faster, you must change your belts and pulleys to achieve a different final drive ratio.

Best Mower:

  • The best mower to use are the free ones.

Blade Deck:

  • Keep the blade deck on.

How much does it cost to build a racing mower?

Building a racing mower typically involves gear up the transmission, removing the cutting blades, and lowering the CG height. It also includes making modifications or alterations to the frame, brakes, steering, engine, and wheels to handle the increased speed. Building a racing mower requires a certain level of knowledge and skill and comes with a financial cost. The typical cost for building a racing mower ranges from $15 for basic modifications to $50 or more for a full-scale build. Racing costs are typically around $50, while the cost of transporting and supporting the equipment can range from $15-20. The horsepower of a typical riding mower racing machine is between 10 and 50, while the race weight ranges from 204-272 kg (450-600 lb).

Are there any specialized parts I need for a racing mower?

Yes, there are specialized parts that are necessary for a racing mower. This includes an engine, centrifugal clutch, sprockets, transmission, steering wheels, axles and hangers, electrical components, wheel systems, gas lever, and some other high endurance engine upgrades. Additionally, you may need to replace the flywheel, governor, rod and piston, and camshaft with high-quality billet parts in order to make the engine lighter and faster.