VJR110, cylinder head

KYMCO VJR oversize Cylinder Head
Why do we need to purchase Taida big bore valve cylinder head when go with the Taida boring cylinder? When use the big bore valve cylinder will make the air easy in and out, and the combustion chamber will work bigger than usually. The upgraded cylinder can increase the efficiency of the intake and exhaust, and then get more power.
( オーバーサイズバルブ )
KYMCO VJR110 oversize cylinder head
VJR-02019.5/17 VJR oversize cylinder head 19/17 ( fit 58.5~59 mm cylinder )
VJR-02021/19 VJR oversize cylinder head 21/19 (fit 59~63 mm cylinder )
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Especificación detallada

KYMCO VJR kit de válvula enorme
VJR-020-V VJR kit de válvula enorme 19/17
VJR-02019.5/17 VJR cabeza de válvula enorme 19/17
VJR-02021/19 VJR cabeza de válvula enorme 21/19