The 2012 Polaris PRO RMK 155 is a high-performance mountain snowmobile engineered for aggressive backcountry riding, prioritizing deep snow capability and agility. Building on Polaris's long heritage in powersports, this model features a Pro-Ride chassis for optimized weight distribution and rider-forward ergonomics, complemented by the RMK front and PRO t-flex rear suspension systems designed for superior deep snow handling. Its 155-inch track with aggressive lugs ensures maximum traction, while the 599cc, liquid-cooled, 2-stroke engine, managed by an Electronic Fuel Injection system and R.A.V.E. ignition, delivers robust power. This snowmobile represents a culmination of decades of RMK lineage, manufactured in Roseau, Minnesota, and is recognized for its lightweight design and agile performance. This comprehensive service and repair manual provides detailed workshop information for the 2012 Polaris PRO RMK 155 600. It covers all essential areas, including workshop service and repair procedures, maintenance schedules, troubleshooting guides, and diagnostic information. The manual offers in-depth instructions for engine disassembly, assembly, and tuning, as well as servicing for the fuel, ignition, cooling, exhaust, drive, suspension, braking, steering, and electrical systems. It also details bodywork and plastics repair, clutch calibration, and includes comprehensive wiring diagrams. Designed for professional technicians and experienced DIY mechanics, this manual aims to equip users with the knowledge necessary to maintain, diagnose, and repair the vehicle effectively, ensuring optimal performance and longevity.