Hoca 52mm QMB139 Performance Head, Part #169-343

Hoca 50cc QMB139 4-stroke 52mm, performance cylinder head. Replaces Cylinder Heads with 64mm Valves. Short Valve Style. Intake Valve Diameter: 21.5mm. Intake Port Diameter: 24mm. Exhaust Valve Diameter: 18.9mm. Exhaust Port Diameter: 22mm. Valve Length: 62.3mm (compatible with 64mm Short Valve Style Heads). Does Not Include Camshaft.