How Fast is a 400cc Go Kart? Race to 55 MPH
As a passionate go kart enthusiast, one of the most common questions I get is "how fast is a 400cc go kart?". From my experience testing karts and engines, a 400cc gas-powered go kart can hit top speeds of up to 55 mph (88 km/h) under optimal conditions.
Engine Size Matters
When it comes to speed, engine size plays a major role. CC stands for "cubic centimeters" and refers to engine displacement – essentially the cylinder capacity available for air/fuel mixing. More cc‘s means more power potential.
- 50cc – Up to 30 hp, common for rental karts and kids models
- 125cc – Up to 15 hp, recreational and entry-level race karts
- 250cc – Up to 40 hp, pro-level racing karts
- 400cc – Up to 25 hp, powerful recreational models
As you move up in cc sizes from 50cc to 400cc, there are huge gains in horsepower. More hp equals faster acceleration and higher top speeds.
Factors Impacting Top Speed
While engine size sets the upper limit for velocity, there are many other elements that affect real world speed:
- Gearing – The sprocket sizes determine torque and rpm range
- Weight – Heavier karts take more power to accelerate
- Chassis/Suspension – Must handle speed while cornering
- Tires – Stickier racing tires grip better at high speed
- Driver – Experience and skill make a difference
Between gear setups, kart configurations and driver ability, actual speed varies widely even for a fixed 400cc engine.
Speed Capabilities by Kart Type
- Kids Karts – Up to 12 hp, 30 mph top speed
- Rental Karts – Up to 15 hp, 45 mph top speed
- Flat Track Racers – Up to 40 hp, 90 mph top speed
- Superkarts – Up to 100 hp, 150 mph top speed
Kids models focus on safety and simplicity rather than all out speed. Rental karts strike a balance for novice drivers. Racers chase the limit. While a 400cc engine itself enables 55+ mph potential, achieving that in a safe controllable kart requires an advanced chassis, suspension and tires.
Go Kart Speed Guide by Class
| Class | Engine Size | Top Speed |
|---|---|---|
| Kids | 50cc | Up to 30 mph |
| Rental | 200cc | Up to 45 mph |
| Entry Level Race | 125cc | Up to 60 mph |
| Pro Race | 250cc | Up to 90 mph |
| Superkart | 500cc | 130+ mph |
Responsible High Performance Driving
While tempting to squeeze every ounce of velocity from a 400cc kart, exercise restraint. High rates of speed must be balanced with driving skill. Safety gear like helmets, neck braces, gloves and suits are essential. Only push limits at controlled, closed-course tracks with sufficient runoff room. Avoid public roads.
Like any powerful machine, respect the equipment and understand your abilities before seeking thrills. Even expert racers suffer crashes at 100+ mph – and karts lack safety cages or restraints. As they say… "more goes faster, less goes farther". Focus on consistency, technique and chassis dynamics rather than peak speed alone. That mentality leads to better lap times and more enjoyment regardless of rated horsepower.
Have you driven a 400cc go kart? Share your experiences below!
