The John Deere 340 Cyclone, produced between 1972 and 1977, represents a robust snowmobile engineered for performance and durability. Building on John Deere's established reputation for reliable outdoor equipment, the 340 Cyclone was part of the brand's significant entry into the snowmobile market during the 1970s. These machines were known for their solid construction and dependable operation, making them a noteworthy option for recreational use during their production period. This comprehensive workshop repair service manual provides detailed information for all models, engines, trims, and transmission types of the John Deere 340 Cyclone from 1972-1977. It covers essential areas including engine service, fuel and electrical systems, powertrain, suspension, and general maintenance procedures. The manual offers professional-level diagnostics, step-by-step repair instructions, and accurate wiring diagrams, designed to assist owners and independent repair technicians in effectively maintaining and repairing their snowmobiles, thereby ensuring optimal performance and longevity.