Sutmorly centrifugal clutch assembly for go-karts & mini-bikes — 1" bore, 14-tooth #40/#41/420 sprocket, heavy-duty

This clutch assembly combines a robust 1" bore for engines above 6.5 HP with a 14-tooth drive sprocket sized for common #40/#41/420 roller chain. Built for hobbyists and small-vehicle builders, the unit bolts onto standard engine shafts to give controlled engagement via centrifugal shoes, delivering smooth takeoff without a manual clutch lever. The product is popular in Prokart, Cadet, Fun Kart and buggy applications and includes a three-month warranty for added purchase confidence.

How does this clutch fit on my engine and drivetrain?

The Sutmorly clutch uses a 1" bore to mount securely on engine output shafts commonly found on engines larger than 6.5 HP (and up to about 13 HP). Its 14-tooth sprocket matches #40/#41/420 roller chains, so it replaces or upgrades directly without re-sprocketing in many setups. Installation requires correct keying and torque to the engine shaft and alignment to the driven sprocket to avoid premature wear.

• 1" bore accepts standard keyed shafts for small gas engines
• 14-tooth sprocket tuned for #40/#41/420 roller chain
• Fits engines generally between 6.5 HP and 13 HP with proper mounting
• Requires alignment, proper chain tension, and correct hardware torque

What performance can I expect during normal use?

Engagement is centrifugal: the clutch shoes expand as rpm rises, connecting the engine to the chain smoothly. This provides predictable takeoff for go-karts and mini-bikes, reducing stalling and harsh starts compared with direct-drive setups. Durability depends on correct application and staying within recommended vehicle weight limits to avoid overheating.

• Smooth automatic engagement at rising engine RPMs
• Reduces stalling and eases low-speed control for novice drivers
• Reliable for recreational and competitive fun-kart use with proper maintenance
• Excessive load or weight will shorten service life—observe weight limits

Are there limits or maintenance steps I need to know?

Yes. The clutch is engineered to move a limited mass; exceeding that limit causes overheating, accelerated wear, and possible failure. Keep the combined kart and rider weight under about 400 pounds and follow routine checks for sprocket teeth, chain wear, and shoe condition. Regular chain lubrication, correct tension, and ensuring the clutch spins freely at idle are basic maintenance steps.

• Recommended maximum combined weight ~400 pounds for typical long life
• Inspect shoe material, sprocket teeth, chain tension, and alignment regularly
• Lubricate chain and replace worn parts before heavy use
• Three-month warranty covers manufacturing defects as pictured

Which vehicles and projects pair best with this clutch?

This clutch is a straightforward upgrade for home-built and replacement applications on go-karts, mini-bikes, buggies, and similar small recreational vehicles. It’s favored in markets such as Prokart and Cadet where reliable centrifugal engagement and compatibility with #40/41/420 chain are desired. Use it where engine output, vehicle weight, and sprocket pitch match the product specifications.

• Well-suited for go-karts, mini-bikes, buggies, and Prokart/Cadet projects
• Replace or upgrade existing 14T clutch/sprocket combinations
• Best with engines rated above 6.5 HP up to ~13 HP
• Designed for #40/#41/420 roller chain drivetrains

Who this is for: Builders, hobby mechanics, and small-vehicle racers who need a reliable centrifugal clutch that mounts on a 1" shaft and uses 14-tooth #40/41/420 chain are the ideal customers. If you’re assembling or refurbishing a go-kart, mini-bike, or similar project and require smoother automatic engagement without adding complex linkage, the Sutmorly assembly offers a compact, compatible solution—provided the vehicle’s weight and engine power fall within the recommended range.