Valve:69mm
Overall Height: 59.5mm
Intake Port Diameter: 18mm
Exhaust Port Diameter: 17mm
Intake Bolt Hole Spacing: 44.5mm
Exhaust Bolt Hole Spacing: 50mm
50mm Cylinder body
Cylinder head&base Gaskets
Left CTV cover gasekts:15.75 Inches(short case)
50mm Pistons sets(Piston, rings, pin, cir clips)
16*13 Roller weights
Cylinder Head Stud bolts
Oil pump and Oil pump Sprokets(33teeth)

50cc QMB139 4-stroke 50mm, Non Emissions（Non EGR） Cylinder Head with 69mm Valves for use with 81.3cc Big Bore Kit! Now you can customize 50cc QMB139 4 stroke big bore engine kits as you need. Then the components can be optional Bore Displacement: 39mm 44mm 47mm 50mm Cylinder Heads: 64mm-EGR 64MM-Non-EGR 69mm-EGR 69mm-Non-EGR Gaskets: Short Cvt Cover case Long CVT cover Case Mufflers: Varieties of Colors More please discover here.