This assembled PAIR-style cylinder head fits CSC go, go MAX and Pug scooters and bikes running 50cc 4-stroke 139QMB engines. Pulsed Secondary Air Injection System (PAIR) is an emissions control system used to lower hydrocarbon (HC) and carbon monoxide (CO) emissions by allowing air into the exhaust flow. 

Original Parts For Scooters SKU 151-240

Specifications:

• Intake Port Diameter: 17mm  
• Exhaust Port Diameter: 17mm
• Valve Length: 69mm  
• Emission Control System: PAIR

Compatibility: 

139QMB-based 50cc / 80cc engines with the following engine codes:

Don't see your engine listed? If the engine code includes "QM" or "FM", this product is compatible with your vehicle.

About CSC: Chicago Scooter Company embodies the spirit of urban mobility with its innovative and stylish lineup of scooters. Designed for city living, their scooters blend functionality, reliability, and modern design, making them the perfect choice for navigating busy streets. Experience the freedom of effortless commuting and explore the city in style with Chicago Scooter Company.