Kitaco NEO 181cc Big Bore Kit – Forged Crank & Head for Honda Grom & Monkey 125

Kitaco NEO 181cc Big Bore Performance Kit – Honda Grom / MSX / Monkey 125 (4-Speed)

The Kitaco NEO 181cc Big Bore Kit is the most comprehensive engine upgrade available for the Honda Grom, MSX125, and Monkey 125. Built around a forged piston, forged crankshaft, and a fully upgraded top end, this kit transforms your 125cc platform into a hard-hitting 181cc powerplant — with the internals to back it up.

What’s Included

• 181cc Forged Piston — high-strength forged construction for increased displacement and durability
• 181cc Hard-Plated Cylinder — precision-bored and plated for longevity under high-performance use
• Piston rings, pin, clips & gasket kit — complete sealing hardware included
• Kitaco Forged Crankshaft — handles the increased power and RPM demands of the 181cc build
• Kitaco Forged H-Style Connecting Rod — stronger than OEM for sustained high-performance use
• High-Performance Camshaft & Head — optimized valve timing and flow for maximum power output
• Reinforced Cam Chain — upgraded for reliability at higher RPM
• Heavy-Duty Valve Springs — prevent float at elevated engine speeds
• Heavy-Duty Cylinder Studs — secure head clamping under increased cylinder pressure
• Hi-Flow Fuel Injector — supports increased fuel demand of the larger displacement

Note: Fuel controller is NOT included and will be required for proper tuning.

Fitment

• Honda Grom (MSX125) — 2013–2020, 4-speed
• Honda Monkey 125 — 1st Gen, 4-speed
• Honda Super Cub / Trail 125 — compatible variants

Emissions & Legal Compliance

This product is intended for closed-course competition use only. It does not meet the emissions regulations for pollution-controlled roads or highways. Qualified Manufacturer Declared “Modified Part.” Not for sale in California.