Things You'll Need
Instructions
Place a 24-inch wood board under one end of your 48-inch wood board and place the other 24-inch piece of wood under the other end. With the three pieces of wood arranged so the two 24-inch pieces are underneath the 48-inch piece and each of the 24-inch pieces are at opposite ends, drill a hole in one end of the 48-inch board that's big enough for a 1/4 bolt.
Drill a hole the same size at the other end. Be sure to drill deep enough for the bolts to be able to pass through the top piece of wood as well each wood board underneath. Now put a 1/4-inch bolt into one of the holes. Insert the bolt from underneath. Make sure there's a washer around the bolt, so the washer is nestled between the bolt and the bottom piece of wood. When the bolt protrudes through the top side of the bottom wood board, slide two washers over it, so there are two washers between the two boards you're attaching.
Now that the bolt is sticking through the hole of the wood board on top, place a washer over it. Slide a nut down over it next and tighten. Don't tighten too much because you want the bottom board it's bolted to to swivel a little. Add a second bolt on top of that one that you make much tighter. The second bolt is just to keep the first one in place.
Using a counterbore bit, drill two holes into the other end of the wood board, then counterbore two more holes below those two. Now counterbore four holes into the bottom wood board. Insert the 1/4 inch 3 inch bolts into each hole and put washers on both tops and bottoms of the bolts but not in between the pieces of wood like you did on the other side. The counterbored holes will stop the bolts from sticking through.
Tightly screw nuts on the bolts, using lock washers underneath them so they can't come loose. Now turn over the cart and at the opposite ends of each 24 inch wood board attach each of the four wheels using 1/4-inch-by-1-inch screws, sliding a washer under each. Turn your kart right side up again. Roll up a towel, so that it's a cushion you can comfortably sit on and duct tape it to the end of your go kart that's opposite the end that swivels. Drill a hole about 8 inches from the bottom of each of the 16-inch wood pieces that will be your brakes. Attach them to each side of your go-kart, using 3-inch hex head screws with washers. Use the same one inch screws you used on the wheels to create stop brakes, positioning one along each side of your go-kart in front of both brakes. Now add steering rope to each of the two eye hooks that you should insert at each end of the front of your go-kart and you're done.