Service manual HH80, HH100, HH120, OH120-OH180, VH80, VH100 First model year engines were named HH140, HH150 and HH160. Changed to OH140, OH150 and OH160 to reflect the overhead valves 78 pages 1.60MB Tecumseh HH80-110112D used on 1971 WorkHorse 800 model 1-0100   Tecumseh HH100-115095B used on 1968 Charger 9 model 1-7931 1968 Charger 9 model 1-7932 1968 Raider 9 model 1-6931 1969 Charger 10 model 1-7041 1969 Raider 10 model 1-6041