Honda-The Power of Dreams
Compact General-Purpose 4-Stroke OHC Engine Series

Tokyo, April 1997 --- This engine series was developed to meet or exceed the compactness and low costs associated with the side valve engines available in this market, thus making it a prime choice in the inexpensive home-use tool market.

Development Objectives

  • Offer a low cost alternative in the home-use tool market, especially in the vertical-type engine segment.
  • Create an engine that is easy to start and use.
  • Combine low exhaust emissions and high output.
  • Offer a quiet, easy to use engine in a lightweight, compact package.

Technological achievements

  • Adoption of a lightweight, low noise and compact OHC construction featuring an internal timing belt allowed optimum location of the valves in the combustion chamber.
  • The adoption of a Uniblock Cylinder layout and an Oblique-split crankcase structure, together with thorough commonalization and integration of parts between the vertical and horizontal versions, have allowed for both lightweight and low cost engines.
  • The adoption of horizontal cross-flow ports and a new mechanical decompressor for easy start-up.
  • The same horizontal cross-flow ports were combined with a compact OHC design and bath-tub type combustion chamber, laying the ground for high maximum power and flat torque characteristics as well as low fuel consumption and clean exhaust emissions.