Taida 52mm Big Bore Kit (88cc) for 49cc/50cc GY6 139QMB Engines

Increase the performance of your 49cc/50cc scooter with the Taida 52mm Big Bore Kit, engineered in Taiwan for riders looking for exceptional reliability and power. Featuring a premium cast-iron cylinder and cast aluminum piston, this kit is designed to deliver increased torque, stronger acceleration, improved hill-climbing ability, and greater overall engine performance while maintaining excellent durability.

When installed with a stock 41.4mm crankshaft, this kit increases engine displacement to approximately 88cc. Pair it with a 44mm stroker crankshaft to achieve approximately 93.4cc.

Features

• Premium Taida cast-iron cylinder for maximum durability and long service life
• Precision-machined cast aluminum piston
• 52mm big bore design for significant horsepower and torque gains
• Excellent heat resistance for daily riding and performance applications
• Precision-honed cylinder walls promote proper ring seating and reduced friction
• Manufactured in Taiwan for outstanding quality and reliability

Important Installation Information

• Before purchasing, measure your engine case with a caliper.
• Cylinder sleeve outside diameter measures 54.45mm.
• Engine case opening must provide a minimum 54.5mm clearance.
• If your crankcase opening is smaller, engine case boring/machining will be required.
• Professional installation is recommended.

Specifications

• Cylinder Bore: 52mm
• Engine Displacement:
  • 88cc with 41.4mm stock crankshaft
  • 93.4cc with 44mm stroker crankshaft
• Cylinder Material: Cast Iron
• Piston Material: Cast Aluminum
• Outer Sleeve Diameter: 54.45mm
• Cylinder Height (without sleeve): 53mm
• Overall Height (with sleeve): 70.3mm
• Country of Manufacture: Taiwan

Package Includes

• (1) 52mm Cast-Iron Cylinder
• (1) Cast Aluminum Piston
• (5) 52mm Piston Rings
• (1) Wrist Pin
• (2) Circlips
• Base Gasket
• Steel Head Gasket
• Cam Chain Tensioner Gasket
• Taida Decal

Compatible Components

• Fits 50mm Cylinder Stud Spacing (70.5mm Diagonal)
• Fits 50-52mm 2-Valve Cylinder Heads
• Fits 41.4mm and 44mm Crankshafts
• Fits 8x14mm Dowel Pins
• Fits 64mm or 69mm Rocker Arm Assemblies
• Intake Studs: M6
• Exhaust Studs: M6
• Cylinder Studs: 168mm / 176mm

Vehicle Compatibility

Fits most GY6 50cc / 139QMB 4-stroke engines, including many Chinese scooters and mopeds such as:

• TaoTao
• Ice Bear
• Wolf
• Roketa
• Tank
• SUNL
• Baja
• BMS (Boreem)
• Panterra
• QLink
• Qingqi
• Kymco 4-Stroke 50cc Models
• Lance
• SYM
• And many other scooters using the 139QMB engine platform with matching dimensions.

Please verify all measurements before ordering. This kit is designed for 139QMB/GY6 50cc engines and fitment should always be confirmed before installation.