Vintage Go Kart Build
Article by Mark Trotta
Several years ago, I took a break from my old car projects and restored an old go kart. Aside from being fun, it was fairly inexpensive (less than $500 including original purchase price).
The Purchase
Resting peacefully in a barn for several decades before I showed up, this old kart had previously had an impact with a tree, leaving the steering linkage slightly bent. A new steering rod was easily fabricated from a piece of threaded rod.
Bird Engineering Go Kart
On the horizontal bar behind the seat, the 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 was a manufacturer of go karts, mini-bikes and three-wheelers. Their products were sold under their name as well as Sears and JC Penney. The company was bought out by Phoenix Engineering somewhere in the 1980s.
Dimensions of this cart are length 57", width 35", height 24", and a wheelbase of 43".
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Prep And Paint Kart Frame
Since the frame was a solid shade of brown rust, I could only guess what the original color was. I decided on a two-tone theme: Allis-Chalmers Orange for the frame, and Industrial Grey for the wheels, pedals, and linkage.
The key to every good paint job is in the preparation.
Everything was stripped down to bare metal before being primed and painted. After cleaning the surface with mineral spirits, masking tape was applied to mask off anything not being painted.
TIP: 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.
After letting the primer dry for several days, the frame was lightly scuffed with 400 wet paper before applying the color coat. I let the paint sit for a few days (out in the warm sun is best), then scuffed with 600 wet paper and applied another color coat.
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Two-Piece Kart Rims
If you've ever tried to install a wheelbarrow or cart tire on a solid rim, you'll appreciate Go Kart Split Rims. They'll save you a lot of time and aggravation on assembly and disassembly.
These rims are five-inch, and have a 4-bolt pattern with a 2-13/16" bolt circle. Two-piece go-kart rims will always require tubes.
Vintage Kart Tire Replacement
The old, worn-out knobbies were replaced with 4.10-3.50 x 5" sawtooth tread tires.
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Tecumseh H25 Flathead
Many old go karts and mini-bikes were fitted with either a Briggs & Stratton or Tecumseh 4-stroke flathead engine. This one had a Tecumseh 2-1/2 HP motor, dated 1968.
The motor was original and fairly complete, but needed a complete overhaul.
Crankshaft, connecting rod, valve seats, cylinder bore, piston and rings are covered in Tecumseh Flathead Engine - Part One
Sheet metal restoration and gas tank repair are covered in Tecumseh Flathead Engine - Part Two
Ignition, carburetor, and engine start-up are covered in Tecumseh Flathead Engine - Part Three
Of course, I could have bought and installed a brand new motor and be done with it, but that would've taken away from the old school look, and a lot of the kart's vintage value.
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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.
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Scrub Brakes
Scrub brakes were fitted to many vintage go karts, including this Bird Engineering kart. Pressing down on the left foot-pedal activates a long rod, which activates the rear cross-rod, which has two pucks of U-shaped metal pivoting on a bolt in front of the rear tires.
Their efficiency is dependent on the type of tires they are being used with.
Sawtooth tread tires, like the ones on this Bird kart, work pretty well with scrub brakes. But, being powered by a 2-1/2 horsepower Tecumseh, the kart's not going very fast to begin with.
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Simple Kill Switch
To stop the motor, a two-pole switch was installed. 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.
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First Ride
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.
After the trial run, my son and I took turns driving around the block to work out a few kinks (the old chain snapped and fell off).
Conclusion
This go kart overhaul took a few months of weekends and about $250 in parts. Supplies included several spray cans of primer and top coat, and about $25 of hardware.
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Related Articles:
Restore An Old Go Kart
Classic Mini-Bike Build
Minibike History
