DHM High Compression Stock Bore Piston – 2022+ Honda Grom & Monkey (50mm, 13:1)

DHMotoring Stock Bore Racing Piston for the 2022+ Honda Grom and Monkey delivers a significant compression boost without requiring a bore kit — a direct bolt-in performance upgrade for your 125cc engine.

Key Features

• ~13:1 high compression ratio for increased power and throttle response
• 50mm stock bore — no machining required
• Larger ring and skirt oiling holes for improved lubrication
• Larger oil spring for better ring seal
• OEM-sized skirt area for proper fitment
• Complete racing piston ring kit with pins and circlips included
• Base gasket spacer and head gasket included
• Compatible with clear big valve head (27/22 valve diameters)

Requirements

• Requires NGK CR9E spark plug
• Minimum 91 octane fuel required
• ECU flash or engine management system required (aRacer or equivalent)
• Professional installation highly recommended
• Ring gaps must be set prior to installation
• Base gaskets must be installed properly — setup sheet included

Recommended Ring End Gaps

• Top ring: .007"–.008"
• Bottom ring: .009"–.010"

Specifications

• SKU: DHM-HCSBP-22
• Weight: 0.6 lbs
• Fitment: 2022+ Honda Grom (JC92), 2022+ Honda Monkey
• Vendor: DHMotoring