HIGH-LIFT PERFORMANCE CAM

FOR QMB139 / 139QMB 4-STROKE 50cc–100cc ENGINES

Unlock the full performance potential of your QMB139 engine with the genuine NCY High-Lift Performance Camshaft. Designed specifically for the 139QMB engine platform, this precision-engineered camshaft increases valve lift and duration, allowing your engine to breathe more efficiently at higher RPM.

Whether you're building a mild 72cc street scooter or a fully built 100cc performance engine, this camshaft helps maximize horsepower, improve throttle response, and extend the engine's usable RPM range.

This is one of the most important upgrades when installing any 47mm, 50mm, 52mm, or 54mm big bore cylinder kit.

• Genuine NCY Performance Product
• High-Lift Performance Camshaft
• Optimized Valve Timing
• Increased Valve Lift & Duration
• Improves Cylinder Filling
• Stronger Mid-Range Power
• Higher RPM Capability
• Increased Top Speed Potential
• Better Throttle Response
• Plug-and-Play Installation
• No Cylinder Head Machining Required
• Precision Ground Cam Lobes
• Hardened Steel Construction
• Factory-Indexed 34-Tooth Timing Gear
• Made for Street & Performance Builds

A stock camshaft limits how much air and fuel can enter the engine. As displacement increases with a big bore kit, the factory cam becomes a restriction.

The NCY Performance Camshaft opens the valves farther and keeps them open longer, allowing your engine to take full advantage of the larger cylinder.

Benefits include:

✔ Stronger Acceleration

✔ Increased Horsepower

✔ Higher RPM Range

✔ Improved Top-End Speed

✔ Better Airflow

✔ More Efficient Combustion

✔ Better Performance From Big Bore Kits

• Stock 50cc Performance Builds
• 47mm (Approx. 72cc / Commonly Sold as 80cc)
• 50mm (Approx. 81cc / Commonly Sold as 100cc)
• 52mm Big Bore Builds
• 54mm Big Bore Builds
• Daily Riders
• Performance Scooters
• Racing Applications

Brand

• NCY

Product Type

• High-Lift Performance Camshaft

Engine Type

• QMB139 / 139QMB
• Air-Cooled
• Single Cylinder
• 4-Stroke

Intake Lobe

• 25.8mm × 21mm × 10.3mm

Exhaust Lobe

• 25.5mm × 21mm × 10.2mm

Timing Sprocket

• 34 Teeth

Cam Bearings

• (2) TPI #16002C3
• Bearing Size: 18 × 32 × 8mm

Construction

• Hardened Heat-Treated Steel

SKU

• 1100-1250

✔ Better Valve Lift

✔ Increased Valve Duration

✔ Improved Airflow

✔ More Mid-Range Torque

✔ Stronger Top-End Power

✔ Faster Engine Response

✔ Higher RPM Capability

✔ Precision Ground Lobes

✔ Excellent Reliability

Fits QMB139 / 139QMB engines including:

Engine Codes

• 139QMA
• 139QMB
• 1P39QMB
• 1P39QMA-2
• YN139QMB
• JJ139QMB
• 139FMA-2
• BD1P39QMB
• BN139QMB
• 147QMD
• Most Other QMB139 Variants

Common Scooter Brands

• TaoTao
• Wolf
• Ice Bear
• Roketa
• Jonway
• Tank
• Peace Sports
• BMS
• Znen
• Bintelli
• Chicago Scooter Company
• SSR Motorsports
• Dongfang
• JMStar
• SUNL
• Gator
• Baja
• Redcat
• Kazuma
• Many Other Chinese Scooters Equipped with QMB139 Engines

For the best results, pair this camshaft with:

✔ 47mm Big Bore Kit (Approx. 72cc)

✔ 50mm Big Bore Kit (Approx. 81cc)

✔ 52mm Big Bore Kit

✔ 54mm Big Bore Kit

✔ Performance CDI

✔ High Output Ignition Coil

✔ Larger Main Jet

✔ Performance Carburetor

✔ Performance Exhaust

✔ Lightweight Roller Weights

✔ Performance CVT

⚠ Professional installation is recommended.

After installation:

• Verify valve-to-piston clearance by rotating the crankshaft by hand before starting the engine.
• Adjust valve lash before initial startup.
• Verify proper cam timing.
• Lubricate camshaft journals and lobes with assembly lube.
• Change engine oil after break-in.

Failure to verify proper valve clearance and cam timing can result in severe engine damage.

For most modified QMB139 engines:

Intake: 0.003"–0.004"

Exhaust: 0.003"–0.004"

Always verify the recommended clearance for your specific engine combination.

NCY is one of Taiwan's most respected manufacturers of high-performance scooter components. Their products are engineered for precision, durability, and reliable performance, making them a trusted choice for enthusiasts and professional builders worldwide.

For maximum performance, combine this camshaft with:

• 54mm Big Bore Cylinder
• 44mm Stroker Crankshaft
• Performance Cylinder Head
• 19–21mm Carburetor
• High-Flow Intake
• Performance Exhaust
• Upgraded CVT Components

Together, these upgrades allow your engine to breathe efficiently, produce more horsepower, and deliver significantly stronger acceleration and top-end performance.

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