Transform your scooter's power band with the RDLN A9 High-Lift Performance Camshaft. Designed specifically for the GY6 50cc (139QMB) platform, the A9 profile is the industry standard for increased performance. By increasing valve lift and extending duration, this camshaft allows your engine to breathe deeper at high RPMs, delivering a significant boost in mid-range torque and top-end speed. Ideal for engines equipped with 72cc–100cc big bore kits.
Model Compatibility
Compatible with 139QMA / 139QMB engine heads found on nearly all 4-stroke 50cc Chinese scooters:
- 139QMA | 139QMB | 1P39QMB | 1P39QMA-2
- YN139QMB | JJ1P39QMB | 139FMA-2 | BD1P39QMB
- BN139QMB | 147QMD | Other QMA and QMB variants
Don't see your engine code? If your 49/50cc 4-Stroke engine code includes "QM" or "FM", this camshaft is likely compatible.
Features
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A9 High-Lift Profile: More aggressive lift than stock for maximum air/fuel intake — ideal for big bore 72cc–100cc builds.
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Pre-Installed Bearings: High-speed, low-friction steel bearings pre-fitted for smooth rotation and long-term reliability under high-heat conditions.
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Hardened Steel Alloy: CNC-machined from high-carbon steel alloy to prevent lobe wear and pitting over time.
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Drop-In Installation: Direct replacement for the stock 139QMB camshaft — no head machining required for standard applications.
Specifications
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Intake Lobe: 26.50mm (±0.05mm)
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Exhaust Lobe: 26.35mm (±0.05mm)
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Material: Hardened steel alloy
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Bearings: Pre-installed 16002/P6 rated ball bearings
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Certification: ISO 9001
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Includes: Complete camshaft with pre-installed bearings
Tuning Tip: To fully realize the gains of the A9 camshaft, pair it with a high-flow intake manifold and slightly stiffer valve springs. Always re-adjust valve lash to .004" (0.10mm) for both intake and exhaust after installation.
Off-Road Use Only: This product is intended for off-road/racing use only. Not legal for use on public roads or on pollution-controlled vehicles in California. Performance upgrades are not covered under warranty.
Model Fitment
Brands: Amstar, Amigo, Ascend, Baotian, Bashan, Blade, Boom, Chicago Scooter Company, Dongfang, Roketa, Baotian, Bashan, BMS, Cool Sports, E Ton, Fly Wing, Eagle, Fly, Italica, Riya, Ice Bear, Jackel, Jet Moto, JCL, Taotao, Peace, JM Star, Jonway, Kazuma, Keeway, KMD, Kymco, Lance, Lifan, Linhai, Loncin, Longbo, Fuxin, Jiajue, Tao Tao, Tao Motors, Trailmaster, Maxtrade, Meitien, Motofino, Motorino, NST, Panterra, Panther, Qlink, Yiben, Red Streak, Redcat, Roketa, Schwinn, Strada, SYM, Tank, Terminator ,Tomberlin, TNG, United Motors, Vento, Vitacci, Wildfire, Wolf, X-Treme, X-Pro, Yongfu, ZNEN, Zhongneng , Zhilong, Geely, Wangye, ZH and more Manufactured by: Taizhou Zhongneng Motorcycle Co.; Jiangsu Zhongneng Motorcycle Co.; Jiangsu Meijunte Technology Co.; Taizhou Qianxin Vehicle Co.; Ningbo Dongfang Lingyun Vehicle Made Co.; Taizhou Zhilong Technology Co.; Zhejiang Jiajue Motorcycle Manufacturing Co.; Zhejiang Gelly Ming Industrial Co.; Taizhou City Senglong Motorcycle Manufacture Co.; Jiangsu Sacin Motorcycle Co.; Jiangsu Linhai Power Machinery Group Co.; Zheijiang TaoTao Vehicles Co.; Zhejiang Senling Motorcycle Co.; Sanmen County Yongfu Machine Co; Taizhou Jiaojiang Zhiwei Motorcycle Manufacture Co.; Huzhou Daixi Zhenhua Technology Trade Co.; Taizhou Zhongneng Motorcycle Co.; Zhejiang Riya Motorcycle Co.; Ningbo Longjia Motorcycle Co.; Taizhou Zhongneng Motorcycle Co.; and more
