Troy-Bilt 31AS2S5GB66 21 179cc 1-Stage 4-Cycle OHV Compact Gas Snow Blower NewTroy-Bilt 179cc 4-Cycle Single Stage 21 in. 179cc 4-Cycle Single Stage 21 in. Snow Blower – 31AS2S5GB66. 179cc Single-stage gas snow blower. Push-button electric start makes starting easy in cold temperatures. 190 Degree E-Z Chute control with manual pitch control. 4-Cycle OHV pull-start.