1.Line,water cooled 2.four-stroke, turbocharged 3.electronically controlled gas system , spark plug ignition , lean-burn ModelWT615.91WT615.92WT615.93WT615. ... 94WT615.95TypeLine, water cooled , four-stroke , turbocharged , electronically controlled gas system , spark plug ignition , lean-burnValve Quantity4Bore × Stroke ...