BLUE LINE
Blue Line Brake Sight Lens Replacement 18mm | GY6 139QMB
Description
Keep your brake fluid level visible and your system sealed with the Blue Line Brake Master Cylinder Sight Lens. This OEM-equivalent replacement lens fits the stock brake master cylinder on 139QMB and GY6-based scooters, and includes an o-ring gasket for a leak-free seal.
Key Features
- OEM Equivalent: Direct-fit replacement for stock brake master cylinders on QMB and GY6 engines.
- Includes O-Ring Gasket: Everything needed for a complete, leak-free installation.
- Wide Compatibility: Fits 50cc through 169cc engines with QM or FM engine codes.
- Affordable Maintenance: Restore brake fluid visibility without replacing the entire master cylinder.
Technical Specifications
- Lens Outer Diameter: 18mm
- Includes: Sight lens + o-ring gasket
- SKU: 1000-1378
Engine Compatibility
139QMB-based 50cc / 80cc engines:
| 139QMA | 139QMB | 1P39QMB | 1P39QMA-2 |
| YN139QMB | JJ1P39QMB | 139FMA-2 | BD1P39QMB |
| BN139QMB | 147QMD | Other QMA models | Other QMB models |
157QMJ-based 125cc / 150cc / 169cc engines:
| 157QMJ | 161QMK | 152QMI | 1P61QMK |
| YN1P57QMJ | 1P52FMI | 154FMI | JJ157QMJ |
| 1P57QMJ | BN157QMJ | BN161QMK-A | Other QMJ, QMK, QMI models |
Tip: Don't see your engine listed? If your engine code includes "QM" or "FM", this lens is compatible with your vehicle.
Product Diagrams
Model Fitments
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