GYMMEDS GY6 50cc Performance Clutch & Variator Kit — 669 Belt, 22-Spline Fit for 50/60/80cc GY6 Short-Case

GYMMEDS GY6 50cc Performance Clutch Set is a complete replacement kit including clutch assembly, variator assembly, and a 669 belt designed to restore or upgrade GY6 50cc–80cc scooters and mopeds.

This kit is built for riders, mechanics, and DIYers who need an all-in-one transmission solution for GY6-type small engines (50cc, 60cc, 80cc). It brings together the clutch bell, clutch assembly, variator with rollers, and a heat-resistant drive belt so you can replace worn parts in one service session. Materials and basic dimensions are specified to help confirm fitment with short-case 139QMB-style engines used in many Taotao, Roketa, Sunl and similar scooters.

Will this clutch kit fit my GY6 50cc scooter engine?

Compatibility is focused on GY6 50cc 4-stroke short-case engines (139QMB) and also lists compatibility with some 60cc and 80cc GY6 derivatives. Check the spline and drum measurements and the variator roller size to ensure a match before ordering. If your scooter model uses a different crankcase or an uncommon shaft size, this kit may not fit without modification.

• Intended engines: GY6 50cc (139QMB) short-case scooters and many 50/60/80cc GY6 variants
• Clutch spline count: 22 splines inside clutch drum/bell
• Spline inner diameter: 12 mm
• Drum outer/inner diameter: 115 mm OD / 105 mm ID

How does the kit improve performance or reliability?

The kit replaces worn clutch components and the drive belt to restore proper engagement and consistent power transfer. Construction uses iron and aluminum components for better heat dissipation and strength, while the belt is made of high-strength, heat-resistant materials to reduce slipping under load. Together these upgrades help maintain torque delivery and reduce premature wear.

• Sturdy iron clutch and aluminum variator for improved heat control
• High-strength 669 belt resists heat and stretching
• Variator rollers sized 16 x 13 mm for predictable CVT behavior
• Complete set reduces compatibility guesses and installation time

What are the key dimensions and parts included?

Knowing the kit’s dimensions and included parts lets you confirm fit before purchase. The clutch drum’s spline area and diameters, roller size, and belt code are all listed so you or your mechanic can compare to the factory parts currently installed on the scooter.

• Included: 1 clutch assembly, 1 variator assembly, 1 669 belt
• Clutch: 22 internal splines; spline area ID = 12 mm
• Drum dimensions: 115 mm outer diameter, 105 mm inner diameter
• Variator rollers: 16 x 13 mm; belt: 669 x 18 x 30 mm

How do I install the clutch and variator kit safely?

Installation requires basic scooter tools and some mechanical experience. Secure the scooter, remove the variator and clutch housings, note original roller orientation and belt routing, then fit the new parts following torque specs and clearance checks. If you’re unsure, have a qualified technician handle the swap to avoid damage.

• Tools typically required: impact wrench or clutch holder, torque wrench, sockets, screwdrivers
• Inspect crankshaft and case for wear before installing the new kit
• Replace belt and rollers together to ensure even performance
• Test ride and recheck fasteners after the first few miles

Who is this for: The GYMMEDS GY6 50cc Performance Clutch Set is suited for scooter owners and mechanics who need a reliable, ready-made transmission replacement for GY6 50cc short-case engines and some 60–80cc variants. It’s ideal for restoring worn drivetrains, improving belt life, and simplifying maintenance with a single-purchase solution. Avoid buying if your engine uses a long-case or nonstandard spline size—measure before ordering.