Category:
        
        
            High-performance All-Terrain Vehicle (ATV)
        
     
    
        
            Target Audience:
        
        
            Outdoor enthusiasts, hunters, farmers, recreational riders requiring a robust and capable off-road machine.
        
     
    
    
        
            Competitors:
        
        
            Honda Foreman, Suzuki King Quad, Polaris Sportsman, Kawasaki Prairie.
        
     
    
    
        
            Engine Type:
        
        
            Liquid-cooled, 4-stroke, SOHC, 5-valve, single-cylinder
        
     
    
        
            Drive System:
        
        
            Ultramatic automatic transmission with On-Command 2WD/4WD and differential lock.
        
     
    
        
            Suspension:
        
        
            Independent front and rear suspension for superior ride comfort and terrain handling.
        
     
    
        
            Braking:
        
        
            Sealed hydraulic disc brakes front and rear.
        
     
 
    
    
    
        
            Engine:
        
        
            Complete overhaul, maintenance, diagnostics, cooling system, lubrication system, fuel system, ignition system, exhaust system, carburetor adjustment and overhaul, internal engine components (piston, rings, crankshaft, cylinder head, valves).
        
     
    
        
            Transmission:
        
        
            Automatic transmission (CVT), clutch operation, belt inspection and replacement, gearbox maintenance, final drive system, differential.
        
     
    
        
            Chassis And Suspension:
        
        
            Frame inspection, front and rear suspension systems (shocks, springs, A-arms), steering system (handlebars, tie rods, rack and pinion), wheel bearings, lubrication points.
        
     
    
        
            Brakes:
        
        
            Hydraulic brake system, front and rear brake calipers, brake discs, brake pads, brake fluid specifications and bleeding procedures, parking brake system.
        
     
    
        
            Electrical System:
        
        
            Wiring diagrams, battery maintenance, starter motor, charging system (stator, regulator/rectifier), lighting system (headlights, taillights, indicators), ignition system components, switches, sensors, fuses, troubleshooting electrical faults.
        
     
    
        
            Bodywork And Controls:
        
        
            Body panel removal and installation, seat, fenders, racks, controls (throttle, brake levers, shifter), cable adjustments, fluid reservoirs.
        
     
    
    
        
            Maintenance:
        
        
            Scheduled maintenance intervals, oil and filter changes, air filter cleaning/replacement, spark plug replacement, valve clearance adjustment, drive belt inspection, lubrication.
        
     
    
        
            Troubleshooting:
        
        
            Systematic diagnostic procedures for common and uncommon issues, fault codes (if applicable), diagnostic flowcharts.
        
     
    
        
            Repair:
        
        
            Detailed step-by-step instructions for disassembly, repair, and reassembly of all major components and systems.
        
     
    
        
            Overhaul:
        
        
            Comprehensive guidance for complete engine, transmission, and major component rebuilds.
        
     
    
    
        
            Depth:
        
        
            Comprehensive, covering everything from basic rider maintenance to complete engine and transmission rebuilds. Includes detailed torque specifications, clearances, and diagnostic procedures.
        
     
 
    
    
    
        
            Engine Type:
        
        
            5-valve SOHC, single cylinder, liquid-cooled, 4-stroke
        
     
    
    
        
            Bore X Stroke:
        
        
            95.0 mm x 93.2 mm
        
     
    
    
    
        
            Horsepower Estimate:
        
        
            Approximately 45-50 HP (varies by region and tuning)
        
     
    
        
            Torque Estimate:
        
        
            Approximately 40-45 ft-lbs (varies by region and tuning)
        
     
    
    
        
            Carburetor:
        
        
            Mikuni BSR42 (single)
        
     
    
        
            Fuel Type:
        
        
            Unleaded gasoline (minimum 87 octane)
        
     
    
    
        
            Oil Type:
        
        
            Yamaha Genuine 4-stroke motor oil or equivalent SAE 10W-40 API SG or higher.
        
     
    
        
            Oil Capacity:
        
        
            2.40 L (2.54 US qt) without filter change, 2.50 L (2.64 US qt) with filter change.
        
     
    
    
        
            Coolant Type:
        
        
            Ethylene glycol based antifreeze mixed 50/50 with distilled water.
        
     
    
        
            Coolant Capacity:
        
        
            1.90 L (2.01 US qt)
        
     
 
    
    
    
        
            Transmission Type:
        
        
            Yamaha Ultramatic V-belt automatic transmission
        
     
    
        
            Drive Modes:
        
        
            2WD, 4WD, 4WD with differential lock (On-Command system)
        
     
    
    
        
            Optional Transmissions:
        
        
            N/A (All models equipped with Ultramatic CVT)
        
     
    
    
        
            Features:
        
        
            Engine braking control, automatic centrifugal clutch, durable V-belt system.
        
     
    
    
        
            Drive Belt Inspection Interval:
        
        
            Every 1,000 km or 6 months, whichever comes first.
        
     
    
        
            Gear Oil Type:
        
        
            Yamalube Gear Oil or equivalent SAE 80 API GL-4.
        
     
    
        
            Gear Oil Capacity:
        
        
            0.25 L (0.26 US qt)
        
     
 
    
    
    
        
            Atv Safety Classification:
        
        
            Not Applicable (ATVs are not typically rated by NCAP or IIHS)
        
     
    
    
        
            Active Safety:
        
        
            On-Command 4WD with differential lock for enhanced traction, engine braking from Ultramatic transmission.
        
     
    
    
        
            Passive Safety:
        
        
            Ergonomic design for rider control, sturdy frame construction, handlebar padding, integrated floorboards with traction pegs.
        
     
    
    
        
            Front Brake Type:
        
        
            Dual sealed hydraulic disc
        
     
    
        
            Rear Brake Type:
        
        
            Sealed hydraulic disc
        
     
 
    
    
    
        
            Engine Oil Change:
        
        
            Every 1,000 km or 6 months, whichever comes first.
        
     
    
        
            Air Filter Cleaning:
        
        
            Every 500 km or 3 months, or more frequently in dusty conditions.
        
     
    
        
            Spark Plug Replacement:
        
        
            Every 5,000 km or 12 months.
        
     
    
        
            Valve Clearance Check:
        
        
            Every 5,000 km or 12 months.
        
     
    
    
        
            Brake Fluid:
        
        
            DOT 3 or DOT 4 hydraulic brake fluid.
        
     
    
        
            Coolant:
        
        
            Yamaha Yamalube Coolant or equivalent 50/50 mix of ethylene glycol antifreeze and distilled water.
        
     
    
        
            Chassis Grease Points:
        
        
            Refer to manual for specific lubrication points (e.g., suspension pivots, steering head).
        
     
    
    
        
            Common Wear Items:
        
        
            Drive belt (CVT), brake pads, wheel bearings, ball joints.
        
     
    
        
            Potential Problems:
        
        
            Carburetor jetting issues in varying altitudes, occasional charging system component failures (regulator/rectifier), CV joint wear with aggressive use.
        
     
 
    
    
    
        
            Manufacturer Focus:
        
        
            Yamaha Motor Company is renowned for its high-performance motorcycles, marine products, and powersports vehicles.
        
     
    
    
        
            Grizzly Lineage:
        
        
            The YFM660F Grizzly marked Yamaha's entry into the powerful 600cc+ ATV segment, building on the success of its smaller Grizzly models. It was a significant player in the performance ATV market for its era.
        
     
    
        
            Key Innovations:
        
        
            Introduction of the 5-valve engine technology to the ATV lineup, along with the industry-leading Ultramatic transmission.
        
     
    
    
        
            Production Period:
        
        
            2002-2005
        
     
    
        
            Manufacturing Location:
        
        
            Japan