为使小型二冲程汽油机适应2000年起实施的第2阶段排放法规,开发了分层扫气方式。其结果,HC+NO_x的排放值降低到原有方式的1/3以下,CO约降低1/2,燃油耗约降低35%,并能有效抑制扫气时混合气成分的窜气。作为层状扫气二冲程系列的扩充,开发了20～43mL的5种机型。 In order to adapt the small two-stroke gasoline engine to the Stage 2 emission regulations implemented since 2000, a stratified scavenging system was developed. As a result, the emission value of HC + NO_x is reduced to less than 原 of that of the conventional method, the CO is reduced by about ½ and the fuel consumption is reduced by about 35%, and the blow-by gas of the mixture component during scavenging can be effectively suppressed. As an extension of the stratified scavenging two-stroke series, five models of 20 to 43 mL have been developed.