Naraku 52.4mm Performance Piston Kit – QMB139 – Part #NK100.64

Naraku 52.4mm Performance Piston Kit is designed as a replacement or upgrade for QMB139 50cc/49cc engines that have been fitted with a 52.4mm big bore cylinder. Perfect for rebuilds, this piston kit helps restore compression, performance, and reliability in your 4-stroke scooter engine.

This high-quality piston set can be used with standard or performance big bore cylinders and offers precise fitment and durable construction for long-term dependability.

Features:

• Genuine Naraku performance replacement piston kit

• Designed for use with 52.4mm bore cylinders (89cc conversion)

• Ideal for maintenance, rebuilds, or upgrades

• Precision-machined aluminum piston for excellent heat transfer and reliability

• OEM-quality fit and finish

Specifications:

• Bore Size: 52.4mm

• Wrist Pin Diameter: 13mm

• Compression Height: 20mm (center of wrist pin to piston crown)

• Piston Height: 36.3mm

• Fits all QMB139-based 4-stroke 50cc scooters with a 52.4mm big bore kit

• Compatible with both stock 41.4mm stroke (89.3cc) and 44mm stroker crank (94.9cc) setups

Includes:

• Piston

• Wrist Pin

• Circlips (x2)

• Piston Rings

Compatibility:

• QMB139 50cc / 49cc engines

• GY6-based scooters