Honda Navi 125cc Big bore kit

This is the first true bolt-on big bore kit developed specifically for the Honda Navi—no cylinder boring, no case machining, and no permanent modifications required.

Using a 53mm piston, this kit bumps the Navi’s displacement up to 125cc, resulting in a noticeable increase in torque, horsepower, and overall rideability. It’s an ideal upgrade for riders who want more power without turning the install into a full engine build.

What’s Included:

• 53mm cast iron cylinder

• 53mm piston

• Piston rings

• Piston pin

• Piston clips

• Complete gasket set (cylinder head, base, and timing chain tensioner)

Recommended Add-Ons:

To get the most out of this kit, we recommend pairing it with a performance camshaft and an upgraded carburetor setup to improve airflow and fully capitalize on the added displacement.