Carkio centrifugal clutch for go-kart 10-tooth 3/4" (20mm) bore — #40/#41/#420 chain fit, metal durable black

Carkio's 10-tooth centrifugal clutch is a durable aftermarket clutch that fits 3/4" (20mm) crankshafts and drives #40, #41, or #420 chains for small engines up to ~8hp.

This compact centrifugal clutch is built for go-karts, mini bikes and small engine projects that require reliable engagement without manual shifting. Made of metal with a black finish, the unit mounts to the crankshaft using a bolt and washer and includes a 3/16" built-in key for secure coupling. It’s sold as a single replacement clutch — check dimensions and chain size to confirm compatibility before ordering.

What engines and chain sizes does this clutch work with?

This clutch is designed for small horizontal engines commonly used on go-karts and minibikes, covering typical 3.5–7hp units and suitable up to about 8hp in many setups. It accepts standard #40, #41, and #420 roller chains, making it versatile for a variety of drive sprocket configurations.

• Compatible with engines commonly rated 3.5–7hp (usable up to ~8hp).
• Accepts #40, #41, and #420 chains for flexible sprocket choices.
• Intended for horizontal crankshafts where centrifugal clutches are standard.

How does it mount and what are the key dimensions I must verify?

Installation is straightforward: slip the clutch onto the crankshaft, align the built-in 3/16" key, and secure it with the crank bolt and washer. Confirming bore size, outer diameter and tooth count before purchase ensures fitment and proper chain engagement.

• Bore (inner hole): 20mm (3/4").
• Outer diameter: 107mm; total height approximately 55mm.
• Teeth: 10; built-in 3/16" key for crank alignment.

What performance and build qualities can I expect from this aftermarket unit?

As an aftermarket replacement, this Carkio clutch emphasizes durability and everyday functionality rather than OEM branding. Its metal construction and black finish resist wear from chain contact, and the centrifugal mechanism automates engagement as engine RPM rises.

• Metal construction for everyday durability in recreational use.
• Designed to engage automatically as RPMs increase—no manual shifting required.
• Supplied as a single clutch unit; intended as a cost-effective OEM-compatible replacement.

Who is this for: Builders, restorers and hobbyists replacing a worn centrifugal clutch on go-karts, mini bikes, or small engine projects will find this Carkio 10-tooth clutch useful when their machine uses a 3/4" (20mm) crankshaft and #40/#41/#420 chain. If you need set-screw mounting or factory-brand parts, consider alternative models; otherwise this unit serves well as a practical, affordable aftermarket option. Always confirm measurements and chain type against your machine before installing.