2000–2008 Polaris 120 Youth Snowmobile Service Manual (P/N 9921077)

Polaris publication P/N 9921077 (© 2007) covers service and repair of the 2000–2008 Polaris 120 youth snowmobile with the Fuji 121cc four-stroke engine.

Text search, bookmarks, and wiring detail: Service text is searchable, with bookmarks for chapters and individual procedures. Some illustrated specification tables and wiring labels are outside the searchable text. Small lettering in the two wiring schematics is clear when enlarged.

• Engine repair: Engine removal, teardown, reassembly, valve-clearance adjustment, camshaft timing, and automatic de-compression system operation.

• Fuel system: Mikuni BV 18 carburetor overhaul, altitude and temperature jetting charts, fuel-line inspection, and fuel tank removal and installation.

• Driveline and controls: Centrifugal clutch service, drive chain adjustment, and brake and throttle cable inspection and adjustment.

• Steering and front suspension: Ski toe alignment, spindle and bushing service, skag replacement, and tie rod, radius rod, trailing arm, and IFS shock replacement.

• Rear suspension: Skid removal and installation, drive sprocket and driveshaft service, track tensioning and alignment, and rail slide inspection and replacement.

• Electrical diagnosis: Throttle safety-switch tests, RPM limiter and AC voltage regulator information, ignition specifications, and separate wiring schematics for 2000–2007 and 2008.

Written primarily for certified Polaris Master Service Dealer technicians in a properly equipped shop, this manual assumes mechanical knowledge and familiarity with workshop procedures.

Fuji Engine Overhaul and Starting Diagnosis

The engine section covers the cylinder head, piston and rings, connecting rod, crankshaft, and camshaft/valve train. Illustrated tables distinguish standard dimensions from wear limits, including cylinder rebore and oversize-piston data.

Assembly procedures address crankshaft end-play shimming, valve-guide replacement and lapping, governor linkage setup, and break-in after an overhaul. The Engine Component Locations section view and De-Compression System illustrations show internal component relationships.

Recoil starter repair includes disassembly, spring rewinding, reassembly, and operational checks. Separate no-start/poor-running sections examine fuel, ignition, and compression causes, with additional troubleshooting for misfire, stalling, overheating, knocking, and backfiring.

Flywheel-removal notes warn that using the cooling fins to hold the flywheel can break them. Main-bearing-cover instructions also address oil-seal damage during assembly.

Mikuni BV 18 Carburetor and Engine Serial Breaks

The 2006 specifications distinguish carburetor settings for engines up to S/N 0502779 and engines S/N 0600001 and above. Separate jetting charts and fuel-screw settings help identify the applicable calibration before carburetor work.

The fuel-system sections explain pilot, main jet, choke, and needle-valve operation, supported by carburetor section views and an exploded parts diagram. Float level is fixed and nonadjustable; the manual specifies replacement of a damaged or malfunctioning float.

Clutch, Steering, and Track Service

The centrifugal clutch can be disassembled and cleaned when excess grease causes slipping, but it has no individual service parts. Replacement is by complete assembly.

Front suspension procedures include handlebar positioning and rod-end engagement checks. The Front Suspension and Steering exploded view identifies fastener locations and torque applications, while the troubleshooting table addresses darting, excessive steering free play, and tie rod interference.

The Rear Suspension Assembly drawing identifies limiter straps, torsion springs, idler wheels, and torque arms. Driveshaft installation details cover bearing and sprocket positioning and track direction; rail slide inspection includes a wear criterion.

Ignition, Safety Switches, and Wiring

Electrical diagnosis covers the two throttle-lever microswitches and auxiliary stop, tether, and key-switch functions. The Electrical Assembly View and wiring schematics show magneto and ignition components, lighting circuits, and regulator/speed-limiter connections.

Ignition timing, coil resistance, coil clearance, and magneto output specifications support electrical repair. Flywheel fastening data distinguish the earlier nut-and-washer arrangement from the 2008 flange-nut arrangement.

Maintenance and Workshop Reference Data

The maintenance chapter includes a service-interval chart, engine oil changes, lubrication points, spark plug inspection, exhaust checks, and off-season storage. Component-specific torque data and clearance specifications accompany the repair procedures.

The manual addresses burns from hot engine and exhaust parts and hazards from a moving track. Its service precautions also cover secure vehicle support during suspension work.

Printable PDF and Included Pages

Supplied as one printable 79-page PDF, including two introductory pages, five notes pages, and a one-page index. These pages are already included in the total.