Although traditionally go-karts use horizontally mounted motors (with a little modification), it is possible to install a vertical axis mower motor to be the driving force behind a homemade racing machine. You can re-test the speed, freedom and adrenaline of an open road by converting a mower engine into the go-kart you've always wanted.
Method 1 of 6: Remove the Motor from a Lawn Mower
Step 1. Drain the oil
Depending on the engine you're using, you may need to get a pair of pliers to disconnect the spark plug wire and remove the oil drain plug. Use a suitable container to drain the oil and clean up any spills.
It is best to drain the oil from an engine when it is a little warm, as heat allows a faster flow than when it is cold
Step 2. Drain the fuel
Loosen the clamp on the fuel hose before starting to drain the fuel. You can do this by tracing the hose path from the engine to the bottom of the tank. Notice where the hose connects to the mower's carburetor. Use pliers to loosen the clamp, and then slide it up over the hose. Now, you can disconnect the hose and drain the fuel into a bucket.
Step 3. Locate the throttle connection
You can usually find the throttle connection under the carburetor. You will find a cable that you must connect to the throttle. By removing the screw that holds the cable in place, you can easily remove the throttle connection.
Step 4. Find the starter motor
This piece is located on the side of the motor and will be shaped like a small can. The electric starter of the mower will have a red battery connected. You can use a wrench to loosen the cable from the starter motor.
Step 5. Remove the necessary nuts and bolts
At the base of the mower motor is the frame, which is where the motor normally sits. Place a wrench on the bolt and use another to hold the nut under the frame of the mower. Next, unscrew the bolts that hold the motor in place.
Step 6. Remove the drive belt
You will find this belt on the crankshaft pulley under the engine. Lean the engine forward slightly and pull the drive belt off its pulley.
Step 7. Remove the motor
Grasp the motor firmly with both hands, lift it from the mower frame and carefully set it aside in a safe place.
Method 2 of 6: Prepare for Installation
Step 1. Measure the size of the motor
You are going to need a kart frame that is capable of accommodating the size and weight of the engine. Most 5 to 7 horsepower engines will fit a standard size kart. The vertical shaft motor you choose can be from a hand mower or a tractor-mower. Both can be used for the go-kart.
Larger engines in the 13-22 horsepower range (typically found in a mower-tractor) can destroy the transmission or go-kart
Step 2. Choose a suitable go-kart frame
You should look for one that can comfortably support the mower's vertical axis motor and gearbox. The gearbox must have a transmissionless shaft configuration.
Step 3. Use chalk to draw a basic life-size design of the frame
This will give you a better idea of the dimensions that will be comfortable for the frame.
Most of the frames have a width that varies between 1/3 and 2/3 of the distance between the axles of the kart, and the wider models provide better stability
Method 3 of 6: Assemble the Frame
Step 1. Cut out the bumper frame and drill holes for the tube padding
You should round the edges of the bumper by connecting the vertical pieces that are attached to the frame and the horizontal piece parallel to the rear piece of the frame with a short connector cut at a 22.5 degree angle. Drill holes for the tube padding in the rear of the bumper.
Drill 5/16 inch (8 mm) centered holes through the bumper cushion padding 1 1/8 inch (7 cm) from the end of the padding
Step 2. Install the axle
Cut a 1 by 1-inch section of square tubing and weld the bolts at the ends. A 6 inch (15 cm) bolt will be located on the driver's side of the kart, while a 4 inch (10 cm) bolt will be located on the passenger side. Weld the axle under the base of the frame.
You should always wear the proper protective equipment when welding. Otherwise, this could pose significant harm to you
Step 3. Install a floor
A 16 gauge piece of sheet metal should be sufficient for the go-kart floor. Use the drawings above to drill holes in the sheet metal for the seat retaining bolts.
Step 4. Weld on a clamp for the seat
You should hook both outside sides of the kart frame with 3/16 gauge flat plate. This is where you will install the bench for the seat.
Method 4 of 6: Assemble the Steering Column, Tabs, and Axle Brackets
Step 1. Cut and install the steering column
You will need to cut a 3/4 x 11 gauge section of pipe and weld it to the steering tabs. Insert an additional 1 inch (2 cm) spacer loosely along the axle near the steering ring, turning the axle slightly near the ring if it is too tight. Drill a three-hole pattern with the holes equidistant from the center of the washer on the end of the axle.
Step 2. Cut the steering ring and relieve the derailleur clamp
Make your cuts at a 39-degree angle for the hoop. At this point, you should verify that all measurements on the steering mount are correct and allow a full range of motion for the kart.
The ring and shaft should be located at a 90 degree angle to each other
Step 3. Add rest tabs for the brake and throttle
These 2-inch long, 3/8-inch diameter tabs hold the pedals in their rest positions and fully forward. The tab closest to the center of the frame should be attached a maximum of 1 cm (½ inch) past the cross piece that the steering column is attached to. The second tab should be installed 3.5 cm (1 3/8 inch) after the first.
Step 4. Attach the axle brackets
You are going to weld them to the front axle of the kart. The axle should have a clearance of 2 cm (1 inch) above the front axle.
Step 5. Install a footrest
Use a 3/8-inch rod in a vise to hammer it into the shape of the passenger footrest, if applicable. This will prevent your feet from resting on the reinforcement bars.
Step 6. Don't forget the brake band bolt
This bolt will serve as a pivot for the brake band. Weld a 3/8-inch round bar to the 1.5-inch (4-cm) frame after the axle.
Method 5 of 6: Assemble the motor mount, brake rod, and accessories
Step 1. Install the motor mount
Make sure the grooves in the motor mount allow it to slide slightly forward. Then, fix the bracket in place. Dimensions are deliberately not included here, as the size of the bracket may change depending on the engine.
- The motor bracket needs to be welded together as the final step to build the kart.
- The bracket must be able to hold the mower motor in the horizontal position.
Step 2. Attach the lug of the throttle cable guide
About 4 inches (10 cm) from the center of the accelerator pedal bolt hole, weld this tab to the kart at a 45 degree angle.
Step 3. Install the guide tab on the brake rod
Take the brake rod and thread it onto the flange, bending it to fit the brake band. Then, take the tab with the rod inserted and solder it to the kart.
Step 4. Bend the brake rod to shape it
Bend this ½-inch (½-cm) round rod so that it forms an angle and matches the brake pedal assembly. Cut the length of the brake rod as needed and weld the eyebolts to the rod with a spring loaded brake pedal installed.
Step 5. Install a seat
Many kits do not bolt the seats directly to the kart. If this is the case, you should use a simple frame and screw it onto the seat clamps. You should cut the seat at a 37.5 degree angle to get a 105 degree tilt for the backrest.
Step 6. Choose the side rails
There are many different designs you can use, but the traditional side railing is made up of three pieces joined together to form a rectangular railing with the side and back of the frame.
Side rails are an optional addition to the kart
Step 7. Weld the motor bracket and attach the accessories
Once you are done with the go-kart body, you can now weld the bracket to the frame. Once the welding is complete, you can add tires, seat padding, and all other necessary equipment to the vehicle.
Method 6 of 6: Install the Vertical Motor and Gearbox
Step 1. Screw the motor and gearbox to the bracket
The location of the engine is not as important as that of the gearbox. To properly install the gearbox, you need to align it with the gear on the rear axle and then screw it into place.
Step 2. Change the gearbox pinion size
A pinion is a gear sprocket inside the gearbox that controls the gear ratio, which is another name for the gearbox. Your target gear will have about 16 teeth.
Step 3. Use the slip clutch on the mower hand strap
One end of the clutch must be installed on the engine, with the protruding side of a pinion that connects to the gearbox. If you don't have a manual belt slip clutch, you can get a centrifugal clutch from your local auto parts store and use it instead.
The ratio of the engine to the transmission should be 1 to 1
Step 4. Connect a throttle cable to the throttle link on the carburetor
Now you can clean all the oil residue from the kart, but do it carefully. You should always wait long enough for the materials you are going to work on to cool down (such as the motor or welding) before applying a cleaning product.
- This simple go-kart should meet the needs of the average user. However, the average user may find it difficult to convert a vertical axis motor and drive the horizontal axis plane.
- Most karts use a centrifugal clutch and horizontal shaft motor, and not a mower motor. Using the proper motor will make installation easier.
- If, instead, you want to buy a used horizontal shaft motor, you can consult local classifieds for industrial equipment, such as pressure washers, mulchers, brush cutters and generators. These machines usually use horizontal axis motors.
- When welding, you must wear all appropriate safety equipment (including a welding mask, gloves, and tight-knit clothing).
- Wait until the engine cools down before refilling the fuel or oil tank to avoid explosions and fires.
- Drive the kart only on your own property or designated areas. You are probably unknowingly breaking the law if you drive it on the streets.