Category:
        
        
            Off-road, Motocross/Enduro (Lightweight Class)
        
     
    
    
        
            Competitors:
        
        
            Competed against models like KTM 125 EXC, Yamaha YZ125, Suzuki RM125, Honda CR125R of the era.
        
     
    
    
        
            Engine Type:
        
        
            Torquey 125cc 2-stroke, liquid-cooled (check specific model variant, some may be air-cooled, but WRK usually implies water-cooled)
        
     
    
        
            Suspension:
        
        
            Long-travel suspension for off-road capability, typically featuring adjustable front forks and a monoshock rear.
        
     
    
        
            Handling:
        
        
            Known for agile handling and maneuverability in technical terrain.
        
     
    
        
            Performance:
        
        
            Emphasis on tractable power delivery suitable for trail riding and entry-level motocross.
        
     
 
    
    
    
        
            Engine:
        
        
            Complete engine overhaul, internal components, cooling system, lubrication system
        
     
    
        
            Transmission:
        
        
            Gearbox operation, clutch assembly, shift mechanism, lubrication
        
     
    
        
            Chassis:
        
        
            Frame, suspension (front forks, rear shock absorber), steering, wheels, hubs
        
     
    
        
            Brakes:
        
        
            Front and rear brake system servicing, hydraulic components, pad/shoe replacement
        
     
    
        
            Electrical:
        
        
            Ignition system, lighting, charging system, wiring diagrams, battery maintenance
        
     
    
        
            Fuel System:
        
        
            Carburetor tuning and overhaul, fuel tank, fuel lines, fuel pump (if applicable)
        
     
    
        
            Exhaust System:
        
        
            Exhaust pipe and silencer maintenance
        
     
    
        
            Bodywork:
        
        
            Body panels, seat, fenders, graphics
        
     
    
        
            Maintenance:
        
        
            Scheduled maintenance, fluid changes, lubrication points
        
     
    
        
            Troubleshooting:
        
        
            Diagnostic procedures for common issues
        
     
    
    
        
            Estimated Pages:
        
        
            ~200-300
        
     
    
    
        
            Type:
        
        
            Workshop Service Repair Manual (OEM Equivalent)
        
     
    
    
    
    
 
    
    
    
        
            Engine System:
        
        
            Detailed breakdown of the 125cc 2-stroke engine, including cylinder, piston, crankshaft, connecting rod, seals, and gaskets. Specific torque values for critical fasteners.
        
     
    
        
            Cooling System:
        
        
            Air cooling system analysis, fin cleaning, and general condition checks.
        
     
    
        
            Lubrication System:
        
        
            2-stroke oil/fuel mixture recommendations, gearbox oil specifications and change intervals.
        
     
    
        
            Transmission System:
        
        
            6-speed gearbox service, clutch operation and adjustment, shift lever linkage.
        
     
    
        
            Fuel Delivery System:
        
        
            Dell'Orto PHBH carburetor specifications, jetting, float level adjustment, and cleaning procedures. Fuel filter inspection.
        
     
    
        
            Ignition System:
        
        
            CDI ignition timing, spark plug specifications (type, gap), and coil testing.
        
     
    
        
            Suspension System:
        
        
            Front telescopic forks (oil type, level, seal replacement), rear monoshock (pre-load adjustment, damping characteristics).
        
     
    
        
            Braking System:
        
        
            Front disc brake caliper and master cylinder service, rear drum brake adjustment and shoe replacement. Hydraulic fluid type (DOT 3/4).
        
     
    
        
            Electrical System:
        
        
            Wiring diagrams for all electrical components, including lighting, horn, and kill switch. Battery specifications and charging system diagnosis.
        
     
    
    
        
            Engine Rebuild:
        
        
            Complete engine disassembly, cleaning, inspection, and reassembly with replacement part recommendations.
        
     
    
        
            Carburetor Tuning:
        
        
            Step-by-step guide for adjusting air-fuel mixture, idle speed, and throttle response.
        
     
    
        
            Suspension Servicing:
        
        
            Fork seal replacement, fork oil change, rear shock absorber adjustments.
        
     
    
        
            Brake Maintenance:
        
        
            Brake fluid bleeding, pad/shoe replacement, caliper/drum servicing.
        
     
    
        
            Electrical Diagnostics:
        
        
            Troubleshooting common electrical faults using wiring diagrams and multimeter testing.
        
     
    
        
            Wheel And Tire Service:
        
        
            Tire pressure recommendations, wheel bearing maintenance, spoke tensioning (if applicable).
        
     
    
        
            Cleaning And Lubrication:
        
        
            Points for regular cleaning and lubrication of moving parts.
        
     
    
        
            Troubleshooting Guides:
        
        
            Problem-solution tables for ignition, fuel, starting, and running issues.
        
     
    
    
        
            Depth:
        
        
            Comprehensive OEM-level detail for DIY repairs, professional mechanics, and in-depth understanding of the machine.
        
     
 
    
    
    
        
            Engine Type:
        
        
            Two-stroke, single-cylinder
        
     
    
        
            Displacement:
        
        
            123.5 cc (approx.)
        
     
    
        
            Bore X Stroke:
        
        
            54 mm x 54 mm (typical for this era and displacement)
        
     
    
        
            Cooling System:
        
        
            Liquid-cooled
        
     
    
        
            Carburetor Model:
        
        
            Dell'Orto PHBH 28 AS (common fitment)
        
     
    
        
            Ignition:
        
        
            CDI (Capacitor Discharge Ignition)
        
     
    
        
            Compression Ratio:
        
        
            Typically around 7.0:1 to 8.0:1 (check manual for exact spec)
        
     
    
    
        
            Horsepower:
        
        
            Approx. 25-30 HP (estimate, actual may vary)
        
     
    
        
            Torque:
        
        
            Not typically quoted for this class, but focused on mid-range pull.
        
     
    
    
        
            Fuel Type:
        
        
            Unleaded gasoline with 2-stroke engine oil mix
        
     
    
        
            Oil Mix Ratio:
        
        
            Typically 40:1 or 50:1 (refer to manual for precise recommendation)
        
     
 
    
    
    
        
            Oil Change Gearbox:
        
        
            Every 10-15 hours of riding or annually. Check for contamination.
        
     
    
        
            Air Filter Cleaning:
        
        
            Clean after every few rides, depending on dust conditions. Replace filter element when worn.
        
     
    
        
            Spark Plug Inspection:
        
        
            Inspect and clean/replace every 10-20 hours of riding. Check plug gap regularly.
        
     
    
        
            Top End Rebuild:
        
        
            Recommended every 50-100 hours of riding for optimal performance and to prevent catastrophic failure. Manual will detail piston, rings, and cylinder inspection.
        
     
    
        
            Chain And Sprockets:
        
        
            Lubricate chain every 200-300 miles or after washing. Inspect for wear and tension at regular intervals. Replace chain and sprockets as a set.
        
     
    
    
        
            Coolant:
        
        
            Ethylene glycol-based antifreeze mixed with distilled water (50/50 ratio). Check manual for specific coolant type.
        
     
    
        
            Brake Fluid:
        
        
            DOT 3 or DOT 4 (refer to manual for exact specification).
        
     
    
    
        
            Engine Seals:
        
        
            Leaking crank seals or transmission seals can lead to air leaks or gearbox oil contamination. Regular inspection is crucial.
        
     
    
        
            Carburetor Tuning Sensitivity:
        
        
            Dell'Orto carburetors can be sensitive to altitude and temperature changes, requiring periodic fine-tuning for optimal performance.
        
     
    
        
            Suspension Wear:
        
        
            Fork seals and bushings can wear over time, leading to oil leaks and degraded damping. Rear shock absorber may require rebuilding or replacement depending on condition.
        
     
    
        
        Maintenance Schedule Overview
    
 
    
        
            Schedule:
        
        
            The manual provides a comprehensive schedule covering pre-ride checks, daily/weekly tasks, and mileage/hour-based servicing. Crucial for maintaining peak performance and longevity.
        
     
 
    
    
    
        
            Legacy:
        
        
            Husqvarna has a long and storied history in off-road motorcycle racing, particularly in motocross and enduro, dating back to the early 20th century.
        
     
    
    
        
            125Cc Class:
        
        
            The WRK 125 was part of Husqvarna's robust lineup of 125cc two-stroke off-road bikes, popular for their performance and durability.
        
     
    
    
        
            Era:
        
        
            Produced during the late 1980s, a period of significant development in off-road motorcycle technology.