RDLN A9 High-Lift Performance Camshaft

Fits 50cc, 72cc, 80cc & 100cc GY6 139QMA / 139QMB Engines

Take your GY6 engine to the next level with the RDLN A9 High-Lift Performance Camshaft. Engineered specifically for the 139QMB platform, the proven A9 cam profile increases valve lift and duration, allowing your engine to move more air and fuel at higher RPMs. The result is stronger mid-range acceleration, improved throttle response, and increased top-end power—especially on engines equipped with big bore kits and other performance upgrades.

Whether you're building a reliable daily rider or a high-performance GY6 scooter, the A9 camshaft is one of the most effective bolt-on upgrades available.

Performance Benefits

• Increased valve lift and duration for improved airflow
• Stronger mid-range torque
• Higher top-end RPM capability
• Faster throttle response
• Improved overall horsepower
• Ideal for performance and big bore engine builds
• Direct replacement for the factory camshaft
• No cylinder head machining required

Engine Compatibility

Designed for most GY6 50cc four-stroke engines including:

• 139QMA
• 139QMB
• 1P39QMB
• 1P39QMA-2
• YN139QMB
• JJ1P39QMB
• 139FMA-2
• BD1P39QMB
• BN139QMB
• 147QMD
• Most other QMA and QMB engine variants

If your engine code contains "QM" or "FM", this camshaft is generally compatible.

Fits many scooters from:

• TaoTao
• IceBear
• Wolf
• Roketa
• Jonway
• Tank
• SUNL
• Peace Sports
• BMS
• Vitacci
• JMStar
• Lance
• Znen
• Dongfang
• Many other Chinese-built GY6 scooters

Recommended Engine Builds

Perfect for:

• Stock 50cc engines seeking more performance
• 72cc Big Bore Kits
• 80cc Big Bore Kits
• 100cc Performance Builds
• Performance cylinder heads
• High-compression engines
• Ported cylinder heads

Technical Specifications

• Camshaft Profile: A9 High-Lift
• Intake Lobe Height: 26.50mm ±0.05mm
• Exhaust Lobe Height: 26.35mm ±0.05mm
• Material: Hardened High-Carbon Steel Alloy
• Precision CNC Machined
• Pre-installed High-Speed Bearings
• ISO 9001 Manufactured

Premium Construction

• Hardened steel alloy resists cam lobe wear
• Precision-ground lobes for accurate valve timing
• Heavy-duty pre-installed bearings reduce friction
• Built to withstand high-RPM performance use
• Long-lasting durability under demanding conditions

Installation

This camshaft is a direct bolt-in replacement for the factory camshaft.

No machining is required on standard GY6 139QMB engines.

For best performance:

• Reset valve lash after installation.
• Recommended valve clearance:
  • Intake: 0.004 in (0.10mm)
  • Exhaust: 0.004 in (0.10mm)

Performance Tuning Recommendation

For maximum horsepower gains, pair this camshaft with:

• 72cc–100cc Big Bore Kit
• High-flow intake manifold
• Performance carburetor
• Free-flow exhaust system
• Performance CDI
• Upgraded valve springs

These supporting modifications allow the A9 camshaft to reach its full performance potential.

Package Includes

• 1 × RDLN A9 High-Lift Performance Camshaft
• Pre-installed High-Speed Bearings

About RDLN

RDLN is a premium manufacturer of high-performance aftermarket scooter components designed to maximize power, reliability, and durability. Every product undergoes extensive field testing to deliver an exceptional balance of performance, quality, and value. Whether you're upgrading a daily rider or building a race-inspired GY6 engine, RDLN components are engineered to perform when it matters most.