50mm QMB139 Non-Emissions Head - 69mm Valves

50cc QMB139 4-stroke 50mm, Non Emissions Cylinder Head with 69mm Valves for use with 81.3cc Big Bore Kit! (See Related Items)

*You may need to modify your engine case to accommodate the larger cylinder.

• For Use With 81.3cc Big Bore Kit
• Valve Length: 69mm
• Overall Height: 59.5mm
• Intake Port Diameter: 18mm
• Exhaust Port Diameter: 17mm
• Intake Bolt Hole Spacing: 44.5mm
• Exhaust Bolt Hole Spacing: 50mm