If you have a riding lawnmower sitting mostly unused in your backyard with a decent engine and some other decent parts on it there is something more you can do with it then use it to tow wagons. Riding lawn mowers can be used very successfully to build your own go kart. This does not mean using the riding lawnmower as it is as a go kart, it is not balanced for that kind of action, nor does it really drive well as one and it is not safe. You can though put the parts to great use and transform them into a very successful go kart.
If you are interested in using a riding lawn mower to build your own go kart you are going to need the following;
You will also need some basic tools which might include;
Then there are the parts from your riding lawnmower like:
You will need to first take apart your riding lawnmower to see what parts can be used from it. The back wheels will need to be modified as the hubs that have been built into them do not rotate without a keyed shaft. It is possible though to adapt them so that they fit a regular axle of a go kart, just take a 1 inch coupler and weld it to the wheel hub. You can then use a cross bolt to keep the coupler in place and stop the wheel coming off of the shaft of the axle.
For most standard go karts there is a 20 inch wide frame and the wheels are 40 inches apart. The front wheels of the riding lawnmower can be removed to be used, or you could opt to take all of the front axle system from it and then cut it in two to reach the width you need.
Most decent go kart plans have a steering system that is simple to put together from some parts so the lawnmowers steering system can be discarded. Most plans will have something like using plate and tubes to make a steering system but it will help to have good welding capabilities and a drill press at this point. Using a riding lawn mower to build your own go kart means the steering wheel and the steering shaft can be kept to be placed at a later date.
Use your plan to guide you in the construction of the go kart frame, but make sure you have enough room in the garage. Most flat style go karts need a flat floor so that you can ensure the frame is correctly aligned. For some the preference in plans is to have them start from constructing the side profile systems then use cross pieces to mate them together. Basically those side pieces are like bridge trusses so they give the go kart frame some support and constraint. Using a truss system gives a lot more strength to the frame than the flat style kart has, in fact is can be over three times the support. The truss system also does have a nice look to it.
Cut 1x1x0.8 square tubes to the right measurement and align on a board to get the correct alignment before you weld it together to make the frame. 2X4s hold the tubes down, but as they are screwed in place it means the tubes can’t be moved and you get basically a very large looking picture frame at first. Only when the you have a good fit should the tubes be tacked on, and then you can take out the side unit from the fixture. When the side units are made you then put in between the, the center spacer tubes and they can then be tacked. When everything has been tacked in the correct position you can weld it to make it more solid.
Now you the plan should lead you to fitting the plates that hold the seat mounts, the pedals, the steering mechanism and of course the engine plate. For those using a vertical engine you can return to using a riding lawn mower to build your own go kart by cutting out the motor mount from it. It will take some patience and you made need some extra blades for your saws-all and some lube too as you do not want your blade becoming dull straight away. Around a vertical engine drive system you can fit the vertical engine into the frame.
It is true that some go kart builders when doing it themselves will try to use the riding lawnmower’s transmission but usually it is not wide enough, is too heavy and often is quite a complicated process. Some choose instead to buy a right angle transmission second hand but really the above mount and vertical engine option is best solution. You are them not having to add a lot of extra weight and can adapt the engine to the drive.
Now we come to the stage where the rear axle needs to be mounted. Bearing plates that point up off from the frame rails are what hold the axle in place. The bearing plate decides where the wheels are going to be positioned. For a kart that has the right weight distribution the rear axle placement is absolutely critical. Otherwise the steering is going to be way off. Good plans for go karts have a 50/50 distribution that considers the front axle and rear axle’s placement.
When the rear axle has been positioned you need to slide into place the rear sprocket, brake disc and of course then take the rear tires you took from the riding lawn mower and mount them to the axle. At this point you should check the ground clearance you have. For a kart that handles well you should be getting clearance that about the same thickness as a 2×4.
Usually the output shaft of a vertical engine drive has a clutch already mounted on and then you can mount the chain to the rear drive sprocket and clutch. A chain tensioner here is good as there is no need to move the engine system forwards or the rear axle back. There will be enough tension from mounting a roller skate to a hinge system and being spring loaded. When you place the tensioner though make sure it is on the chain’s slack side.
Now it is time to move on to mounting the front steering system which tends to be a 1x1x.125 wall cross tube. On each end it has steering knuckles mounted and some opt to use plates to mount the steering tube with so that you can remove it at some point or move it further forwards or back. You weld a bushing plate to the cross tube to mount the steering shaft and it gets support from a tube that comes upwards from the actual frame. That way the steering wheel stays in position when you them mount the wheel to the shaft. Steering linkage and the steering shaft plate are attached and it is directed to the front wheel knuckles. Be sure you have a good tight fit.
In the plans should be a guide to constructing a wooden seat for the go kart. You then insert a cushion into the wooden frame and cover it with a heavy fabric or vinyl. Use an industrial staple gun to hold it in place on the seat’s back. Plates that were fixed to the fame should have holes where wood screws can be put in to hold the seat in place. The seat’s back should angle at about 15 degrees.
Important when putting in the pedals is to make sure there is spring force that pulls them back into place. Some kart builders opt to have hard spring pulling on brakes and the throttle too. Once the pedals are done it is time to do the brakes. Go kart brakes should float, as if not they bind. You should let the disc float and to the framework you should lock down the brake mechanism. Now you can put in the bottom sheet on the frame so that there are no foot injuries. It can be made from sheet metal and the simplest way to mount it is to drill in self drilling tapping screws that are spaced at 3 inches.
Almost done – it is just time to check over your work and make sure it all feels and looks right. Check there are no wobbling bits, that things are tight where they need to be and check your drive system works. It is essential too that you do several checks on your brakes before riding. A nice safety feature to give your go kart is a stop switch. It is essentially a wire that goes to the point wire so when activated it shorts that point wire which then stops the engine. Using a riding lawnmower to build your own go kart is a longish project depending on the time you have. Expect it to take at least 7 weekends, possibly more.