Koso filter components are designed to support reliable performance with quality construction and straightforward fitment.

*Does not fit 2022+ models Our Koso 4V Head Kit is the ideal engine part to complete the Koso Honda Grom® Big Bore kit. Because of its unique 4 valve design, the air flow and performance are increased.

  • Designed for straightforward installation where applicable

Specifications

  • Cylinder height: 64.2 mm.
  • Gasket thickness: Upper: 0.25 mm | Bottom: 0.5 mm.
  • Piston compression : height: 19.5 mm.
  • Volume: 169.21cc.
  • Squish: 1mm.
  • Cylinder head titration: 13.4 cc.
  • Compression ratio: 12.3 : 1.
  • Valve / Tappet clearance: IN: 0.10 mm EX: 0.17 mm.
  • Camshaft: Torque: 1.71 Hp: 26.26 *measured without air filter & no noise reduction plug.
  • **Requires the use of Iradium spark plug: NGK‑ER9EHIX (part.

Why Buy From Hurtle Gear?

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    In-stock items ship quickly from our WA warehouse for reliable Australian delivery.
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SKU MC623000
Brand Koso
Product Specifications