2012 Yamaha Grizzly 550/550FI 4x4 Owner's Manual (P/N LIT-11626-25–23, LIT-11616-25-06)

• 626 PDF pages across two Yamaha factory publications: 174-page Owner’s Manual, P/N LIT-11626-25-23 (1st edition, March 2011), and 452-page Service Manual, P/N LIT-11616-25-06 (1st edition, April 2011).
• Covers the 2012 fuel-injected YFM5FGB, YFM5FGHB, YFM5FGPB, and YFM5FGPHB Grizzly 550 models. EPS-specific repair and diagnostics apply to the P/PH variants; the shared service volume also contains model-specific 2012 Grizzly 700 material for YFM7FGPB, YFM7FGPHB, and YFM7FGPSEB.
• Explains control and label locations, the multi-function display, On-Command 2WD/4WD and differential-lock operation, pre-operation checks, riding procedures, loading, and scheduled owner maintenance.
• Documents engine removal, cylinder-head and valvetrain repair, piston and cylinder inspection, crankcase separation, crankshaft and oil-pump work, transmission service, and middle-gear setup.
• Details V-belt and primary/secondary sheave service, centrifugal clutch inspection, front and rear CV-shaft disassembly, differential and final-drive repair, shim selection, and gear-backlash adjustment.
• Includes brake hydraulic service and bleeding, wheel hubs, steering stem, tie-rods, knuckles, ball joints, suspension arms, shock-absorber inspection, toe-in, and separate EPS/non-EPS steering procedures.
• Provides fuel-injection, cooling, ignition, charging, 2WD/4WD, and EPS diagnostics with circuit diagrams, self-diagnostic tables, exploded views, special-tool references, torque data, wear limits, and electrical test specifications.

Coverage and Document Scope

The owner’s manual is dedicated to the four Grizzly 550 model codes. The service manual is Yamaha’s shared 550/700 workshop volume, so its specification tables and some procedure callouts carry both engine families. Model identifiers, EPS applicability notes, and separate steering-stem and pitman-arm procedures keep the work on the correct 550 configuration. Within the 550 range, the P/PH models use EPS; the base and H models use conventional steering.

Operation and Routine Maintenance

The owner’s volume maps the controls, instruments, warning labels, specification labels, service points, and storage locations. It explains the multi-function display, drive selector, speed limiter, On-Command switches, differential-lock indicators, override function, brake controls, shock-preload adjustment, carrier loading, and auxiliary DC jack. The pre-ride material covers the engine, final-drive and differential oils, coolant, brakes, throttle, tires, chassis fasteners, lights, and switches before the ATV is put into service.

Routine maintenance is organized by mileage, operating hours, and calendar time. The charts cover valve-clearance inspection, spark-plug condition, air-filter service, engine and gear oils, cooling-system checks, spark-arrester cleaning, V-belt inspection, axle boots, brake pads and hoses, wheel bearings, steering lubrication, battery care, fuses, and lighting. Factory baseline data includes the DOT 4 brake-fluid requirement, cooling and lubricant capacities, OEM MAXXIS MU19/MU20 tire and pressure information, fuse data, and auxiliary-jack limits.

Repair and Overhaul Coverage

The service manual is built around exploded assembly views, removal-order charts, inspection criteria, installation notes, and component-specific tightening data. Engine repair goes well beyond tune-up work: it covers cam timing, the decompression system, rocker arms, valve-guide removal and installation, valve-seat contact, piston rings, AC magneto and starter clutch service, CVT sheaves, clutch components, crankcase sealing, crankshaft installation, oil-pump inspection, shift forks, shift drum, transmission shafts, and middle-gear alignment.

Drive-train repair begins with noise diagnosis and fault isolation, then moves through front and rear constant-velocity shafts, boot-band installation, the front differential, differential motor, rear final drive, pinion and wheel-gear shim selection, and backlash checks. Chassis sections support caliper disassembly, master-cylinder inspection and assembly, brake-pad replacement, wheel and hub work, steering-stem removal, tie-rod and knuckle inspection, ball-joint replacement, and front/rear suspension-arm service.

Cooling and fuel-system chapters cover radiator pressure checks, thermostat testing, water-pump disassembly and seal installation, fuel-tank and pump removal, injector and throttle-body checks, fuel-pressure testing, and throttle-position-sensor adjustment.

Diagnostics, Diagrams, and Technical Specifications

Electrical fault finding is organized by system rather than placed in a generic wiring section. Separate circuit diagrams and troubleshooting paths cover ignition, electric starting, charging, lighting, signaling, radiator-fan control, fuel injection, fuel pump, 2WD/4WD selection, and EPS. The FI and EPS chapters add diagnostic modes, fault-code tables, sensor and actuator checks, and system-specific self-diagnostic procedures.

A separate symptom-based troubleshooting chapter addresses starting failures, incorrect idle, poor medium- and high-speed performance, shifting and clutch faults, overheating, poor braking, unstable handling, and lighting or signaling problems. Particularly useful drawings include the EPS block diagram, lubrication-system diagrams, cooling-system diagrams, cable-routing views, the fuel-injection circuit diagram, and the 2WD/4WD selecting-system circuit diagram.

The special-tool index identifies the sheave spring compressor 90890-04134/YM-04134, crankcase separating tool 90890-01135/YU-01135-B, fuel-pressure adapter 90890-03176/YM-03176, and gear-lash measurement tool 90890-01475/YM-01475. Specification sections supply model-specific torque tables, lubrication data, clearances, wear limits, capacities, and electrical test values for the covered assemblies.

The manual specifically warns against disassembling the EPS unit because doing so can damage it. The differential ring gear and differential gear are factory-matched as a unit; separating them can cause malfunction, and losing differential-motor indexing can leave the indicator display out of step with the actual 2WD/4WD/differential-lock position. The shaft-drive chapter also warns that insufficient backlash after repair is highly destructive to the gear teeth, making the included shim-selection and backlash checks critical final verifications.

Brake hydraulic work, fuel-pressure testing, engine removal, and driveline setup require secure vehicle support, proper fire precautions, and qualified mechanical judgment before the ATV is returned to service.