Go Karting with a Riding Lawn Mower
You may have a backyard mounted mower that became too much work as the deck rotted and the mower stopped working. All the riding mower is good at right now is towing cars, and it’s not very good at it. One thing that is dependable on the ride-on lawn mower is the motor, tires, and a few other essentials for a fantastic go-kart.
Unfortunately the riding mower requires some driving education, a clutch push is required here and an adjustment there for the unit to work. Therefore, using the lawn mower as a makeshift go-kart is neither realistic nor safe.
You had other intentions for this rusty helmet that you have yet to discover. You haven’t figured out how it is possible to transform lawn mower parts into a go-kart that is sure to make everyone smile.
The transformation requires the following:
- Go Kart Plan
- Vertical motor drive
- Pipe for frame work
- Wood, fabric and foam for the seat.
- Rear axle and drive pinion
- Bearings for the rear axle
- Braking system
- Hack Saw of saws, all with metal cutting blades
- Standard wrench set (includes Allen screws, hammer, sockets, locking pliers and screwdrivers)
- Drill or drill press
The rest of the elements of the riding lawn mower can be used for the go-kart. The front tires, the rear tires, the steering gear, the steering wheel, the pedals, and obviously the engine.
Disassembling the mower
To start the mower it must be disassembled to know which parts will work best.
What you will discover is that the rear wheels will require some modification, because the wheel hubs are usually built into the rear wheel and require a keyed axle to make them turn. No problem, the wheels can be adapted to fit a standard kart axle simply by welding a 1-inch coupler to the wheel hub. The coupler is then held in place with a cross bolt, this prevents the wheel from slipping off the axle shaft.
The front wheels can be removed from the mower or the entire front axle system can be cut in two and then widened to the desired width of the kart. Typically the frame width is 20 inches and the wheels are about 40 inches apart.
A good kart plan will have a simple steering system, so in the end it might be easier to scrap the steering system and use the parts that the plan shows. Typically, the plan will allow you to fabricate the steering system from tube and plate. A good knowledge of a drill and a welder is useful here. Keep the steering axle and steering wheel to fit in the kart later.
Go Kart Frame and plan
The frame should be built using the go-kart plan as a guide. A typical flat style kart will require a flat garage floor for proper frame alignment. The go-kart plans I prefer require the side profile systems to be built first and then coupled with cross pieces. The side pieces are similar to the trusses of a bridge and provide a safety measure that acts as a restraint to prevent occupants from spilling. In addition, the truss system provides almost three times more resistance than a flat-style kart. And finally, the truss system gives the kart an aesthetic look, or a cool look.
The frame is constructed of 1x1x.08 square tubing that is cut to the proper dimensions and then attached to a dash-style fixture for alignment prior to welding. The tubes are held in place with 2x4s that are bolted to the board. The 2x4s are positioned so that the tubes cannot be moved and are held in place in much the same way as a photo frame would be built. Once the pieces are properly clicked into place, the tubes can be nailed in place and then the entire side unit can be removed from the fixture.
Once the side units have been built, the center spacer tubes can be placed between the side units and can then also be placed in place. Once the entire frame has been nailed down, then the entire frame can be solidly welded.
Engine plates and mounts
The next step is to attach the plates that hold the pedals, the steering gear, the seat mounts, and the motor plate. If a vertical motor is used, the motor mount of the ride-on lawn mower motor can be cut with a saw, everything. (This will take about 20 minutes for the patient. Make sure you wear ear plugs and have extra blades on hand. Lubricating the blade helps prevent the blade from dulling too quickly).
The vertical motor can be placed in the frame around a vertical motor drive system. Some users will try to use a transmission from a lawn mower, however this can actually be quite tricky, heavy, and not wide enough for the go-kart you are making. Others buy a second-hand right angle drive. The best solution is to use the vertical motor and mount it on the frame without adding a large amount of weight, then adapt the motor to the vertical drive of the motor.
The next phase is to assemble the rear axle according to the go-kart plan. The axle is held in place by support plates that adhere vertically to the frame rails. The bearing mounts in the bearing plate cutout. The position of this plate dictates where the wheels will be located both longitudinally and vertically on the kart frame.
Rear axle location is critical for proper weight distribution, which dramatically affects steering. This is known as a 50/50 weight distribution. A good go-kart plan will take into account the weight distribution and the location of the front and rear axles. Once the rear axle has been attached, slide the rear sprocket and rear brake disc into place and then mount the rear tires on the rear axle and check the ground clearance.
Ground clearance is typically the thickness of a 2×4 for good handling.
The output shaft for the vertical drive of the engine will normally have a mounted clutch. Then the chain can be mounted on the clutch and rear drive sprocket. This is where I like to have a chain tensioner because it doesn’t require the rear axle to move backward or the engine system to move forward. A simple skate mounted on a hinge system (spring loaded, of course) will provide proper chain tension. Make sure to place the tensioner on the slack side of the chain (that is, the lower side of the clutch system).
The next phase is to assemble the front steering system. The front steering system is typically a 1x1x.125 wall cross tube with steering knuckles mounted on each end. I like to mount the head tube with plates so that it can be removed. It also allows the steering system to move forward or backward. The steering axle is mounted to the cross tube by a hub plate that is welded to the cross tube. The steering shaft is supported by a vertical tube that comes from the frame itself. This prevents the steering wheel from rolling side to side, up and down, and in and out.
The steering wheel can then be mounted on the steering shaft. The steering linkage is attached to the steering axle plate and then the linkage is routed to each knuckle on the front wheel. Make sure the steering system is tight and not loose when complete.
The next phase is the settlement. Typically a wooden seat is built. Then a cushion is inserted into the wooden frame. The entire system is then covered with a vinyl material or heavy cloth. The cover is held in place with an industrial-grade stapler at the back of each seat. The seats consist of a seat and a backrest that is angled about 15 degrees. The plates that were mounted to the frame have holes where the wood screws can be screwed into the seat backs to hold the seats in place.
Assembling the pedals
The next phase is to put the pedals in place. The key to the pedals is that they snap back into position with the force of the spring. For the throttle, I like to have a kickback when the engine pulls hard, so when the throttle is released, it slams shut. The same goes for the brake, I like to have a large return spring pulling back on the linkage.
Mounting the brakes
The brakes can now be put on the frame of the kart. The major problem with go-kart brakes is that they float. If they don’t, they will join. The best thing to do is to let the disc float and lock the brake mechanism to make the frame work.
Mounting the bottom plate
The final phase is to place the bottom sheet under the kart. This is essential to prevent foot injuries. Provides a bottom shield that is essential to kart design. The sheet can be made of sheet metal used in conduits. The easiest way to mount the blade is to use a self-tapping, self-tapping screw and drive it with a drill. Space them about 3 inches apart.
Make sure all parts are tight and not wobble. Also make sure the transmission system is working. And, obviously, check that the brakes really work. It is a good idea to have a stop switch, which is basically a wire that goes to the tip wire (usually black). When the switch is activated, it cuts the wire to the frame to stop the engine.
The amount of time required to make such a kart is about 7 weekends, if not more. Be prepared for the long term of this project, but it will be worth it when it is complete.