New, in the package! Genuine 2FastMoto 50cc Large Bore Cylinder Head / 70cc Small Bore Cylinder Head
Yes, this head can be used on either a 50cc or 70cc engine. But you must know what type of piston you are using, to know whether or not this head will work on our 50cc or 70cc engine, here's what you need to do.
If you have a 50cc engine:
Honda made 2 different 50cc Cylinder heads. Compare the Combustion Chamber Size shown below, to your current head. This head will only work with DOMED pistons. If you have a FLAT TOP piston, then you will need our SMALL BORE 50cc head.
If you have a 70cc engine:
Honda made 2 different 70cc Cylinder heads. Compare the Combustion Chamber Size shown below, to your current head. This head will only work with FLAT TOP pistons. If you have a DOMED piston, then you will need our LARGE BORE 70cc head. Occasionally you need to make small modifications to the head, to install it correctly.
Includes everything pictured above
NOTE: The head you receive may look slightly different than what is shown or may look slightly different than your existing head. Numerous variations were produced by Honda over the years, but rest assured that the head will bolt on and perform like new !
Combustion Chamber Size
Outer Bore Size: 47mm
Inner Bore Size: 39mm (fits Hi Dome Pistons)
Intake Valve: Outside Diameter 23mm / Length 66mm
Exhaust Valve: Outside Diameter 20mm / Length 66mm