Vintage Go Kart Build
Article by Mark Trotta
They're fun, they're cheap, they're collectable - but most of all they're fun! Vintage go karts take the motorized world down to its most basic element.
Resting peacefully for several decades before I showed up, this old kart had seemed to have had an impact with a tree years ago leaving the steering linkage slightly bent. Local rodents had made a meal of the original seat vinyl, and the gas in the tank smelled like turpentine.
Bird Engineering Go Kart
On the horizontal bar behind the seat, a tin sticker read "Bird Engineering Inc P.O. Box J Fremont, Nebraska 68025" followed by a hand-engraved serial number. I did a little homework and found that Bird Engineering was founded in 1959, and manufactured go karts, mini-bikes and three-wheelers, selling them under their name as well as Sears and JC Penney. The company was bought out by Phoenix Engineering somewhere in the 1980s.
Since the kart frame was a solid shade of brown rust, I could only guess what the original color of the kart was. I decided on a two-tone theme: Allis-Chalmers Orange for the frame, and industrial grey for the wheels, pedals, and linkage.
Dimensions of this cart are length 57", width 35", height 24", and a wheelbase of 43".
Prep And Paint
The key to every good paint job is in the preparation. Everything was stripped down to bare metal before being primed and painted. I cleaned the surface with mineral spirits, and used painters tape to mask off anything I didn't want painted.
If a kart frame won't fit on your workbench, you can prop it up on wooden horses or with pieces of wood or cinder blocks while painting.
After letting the primer dry for several days, I lightly scuffed the frame before applying the color coat. I let the paint sit for a few days (out in the warm sun is best), then scuffed and applied another color coat. I repeated this procedure three times.
Before you paint, select an area that is well-ventilated, near an open window or open garage door is good. Spray-can paint fumes aren't as harmful as other paints, but good ventilation provides you not only with fresh air, it also helps the finished product dry faster.
Two-piece go-kart rims always require tubes. They really save you a lot of time on assembly/disassembly.
I replaced the worn out knobby tires with 4.10-3.50 x 5" sawtooth tread tires.
Go-Kart Engine Build
Many old go karts and mini-bikes were originally fitted with either a Briggs & Stratton or Tecumseh flathead engine. Those old flathead motors are durable, reliable and easy to repair.
To get the kart project completed faster, I swapped the original non-running Tecumseh H25 flathead for a Briggs & Stratton 5hp flathead.
5-HP Briggs & Stratton Motor
Because the Briggs had not run in a while, it needed a little "freshening up". A few 2x4 strips of wood were used to make an inexpensive engine stand.
The carburetor was disassembled, soaked in parts cleaner, then cleaned and air-dried. For reassembly, a new carb rebuild kit was purchased, which basically consists of a diaphragm and a gasket or two.
After the carb was rebuilt, I cleaned and flushed the inside of the gas tank with kerosene several times, let dry, then repainted it black. I flushed the engine with thin motor oil, then added fresh 10/30 oil and a new spark plug. After 10 to 15 pulls, it started up.
Go Kart Clutch
A centrifugal clutch found on old school go karts does not like "on-and-off" operation. If you drive it this way, the clutch will have a very short life, so it's better to run pedal down or not at all. A solution to this would be installing a torque converter, which also gets more power to the rear wheel.
DIY Steering Wheel
I couldn't fit my "adult-sized" body behind the original dished steering wheel, so I fabricated a flat steering wheel. I took some 5/16" round-stock metal rod and bent it around an old Chevy harmonic balancer propped up in my workbench vise. For the steering wheel hub, I cut a scrap piece of 5/8" round steel tube and welded it to the butterfly-shaped rods.
I sliced two lengths of 5/16" fuel-line hose and wrapped them around the ends of the steering wheel.
Simple Kill Switch
The simplest kill switch is a shoe-string tied around the spark plug wire so you can reach over and yank it to stop the motor. Better yet, wire up a two-pole switch. One wire gets grounded to the frame and the other wire goes to the engine. When you throw the switch, it grounds the ignition and kills the motor. A momentary switch would also work.
In terms of efficiency and stopping power, disc brakes are best. Below disc brakes are drum brakes. Below drum brakes are band brakes. And below band brakes are scrub brakes.
Pressing down on the foot-operated pedal activates the cross-rod, which has two pucks of U-shaped metal pivoting on a bolt in front of the rear tires. So what is there to say in favor of the scrub brake? Well, they're simple, they're cheap, and they're better than using your sneakers.
With everything tightened down and inspected, I fired up the motor, climbed in, and off I went. What a blast! Rolling along six inches above the pavement, neighborhood kids smiling and waving.
Even a quick spin down the street puts a smile on your face!
After the trial run, my son and I took turns driving around the block to work out a few kinks. And that's basically all there was to this vintage go kart restoration; a few weekends of work and about $150 in parts. Supplies included several spray cans of primer, several spray cans of top coat, and about $20 of hardware.