This manual covers the 250 Plonker, a 5-speed variant from a renowned Spanish motorcycle manufacturer known for its innovative off-road and trials machines. Produced likely between the mid-1960s and early 1980s, these motorcycles, often featuring distinctive frame designs and robust two-stroke single-cylinder engines, were built for agile handling and competitive performance. The brand heritage is rooted in engineering excellence, making this model a sought-after machine for enthusiasts and restorers. This factory service repair workshop manual provides comprehensive coverage for the 250 Plonker, offering detailed information essential for maintenance, repair, and restoration. It includes in-depth procedures for the engine, transmission, chassis, electrical system, suspension, and brakes, alongside troubleshooting guides, technical specifications, and exploded diagrams. The manual is designed to assist owners, mechanics, and technicians in understanding and maintaining the vehicle to factory standards, ensuring its longevity and optimal performance. 🏷️ Basic Information Identification Make: OSSA Model: 250 Plonker Model Variant: 5 Speed Codes Engine Code Series: Likely a variant of OSSA's 250cc two-stroke single-cylinder engine series, common in their off-road and trials models. Chassis Code Series: Specific chassis codes would vary by year and sub-model, but generally characterized by OSSA's distinctive frame designs. 👋 Introduction Market Position Target Audience: Owners, mechanics, and restorers of OSSA 250 Plonker motorcycles seeking detailed technical information for maintenance, repair, and restoration. Competitive Analysis Value Proposition: Provides access to factory-level technical data, crucial for the longevity and correct servicing of a classic motorcycle, often unavailable elsewhere. Key Features Features: Instant PDF download, lifetime access, multi-device compatibility, printable pages, comprehensive coverage. Manufacturer Legacy Brand Heritage: OSSA (Orpheo Sadurni SA) was a Spanish motorcycle manufacturer known for its innovative and competitive off-road and trials motorcycles, often featuring unique engineering. 📋 Manual Details Coverage Areas Systems Covered: Engine, Transmission, Chassis, Electrical System, Suspension, Brakes, Fuel System, Cooling System, Lubrication, Bodywork, Troubleshooting. Page Count Estimated Pages: Hundreds (as per product description, indicating comprehensive coverage). Manual Type Type: Factory Service Repair Workshop Manual Language Language: English (presumed, standard for international manuals of this era). Format Digital Format: PDF Download 📖 Manual Coverage Systems Covered Engine Mechanical: Complete overhaul, top-end rebuild (cylinder, piston, rings), bottom-end rebuild (crankshaft, bearings, seals), valve timing (if applicable, though likely piston port), carburetor tuning and overhaul, ignition system service. Transmission Drivetrain: Gearbox disassembly and reassembly, clutch service and adjustment, chain and sprocket maintenance, gear selection mechanism. Electrical System: Wiring diagrams, lighting system service, ignition system troubleshooting, charging system (if equipped), component testing. Suspension Handling: Front fork service (oil changes, seal replacement), rear shock absorber maintenance or replacement, swingarm pivot bearing service. Braking System: Drum brake servicing (shoe replacement, adjustment), hydraulic disc brake service (if applicable, caliper overhaul, bleeding). Pedal and lever linkage adjustment. Fuel System: Fuel tank cleaning and sealing, fuel line replacement, fuel petcock service, carburetor cleaning, jetting, and synchronization. Frame Chassis Alignment: Procedures for checking and correcting frame alignment, steering head bearing adjustment. Wheel Wheel Assembly: Spoke tensioning, rim truing, hub bearing maintenance, tire and tube replacement. Bodywork Cosmetics: Information on fairings, fenders, fuel tank, seat, and other body panels, including removal and installation. Lubrication Points: Diagrams and specifications for all lubrication points on the motorcycle. Procedures Included Routine Maintenance: Oil changes, filter cleaning/replacement, chain lubrication and adjustment, spark plug replacement, air filter service, brake adjustments. Troubleshooting: Diagnostic charts for common starting problems, running issues, electrical faults, and performance degradation. Repair Overhaul: Step-by-step instructions for complete engine rebuilds, gearbox overhauls, suspension component replacement, and major component repairs. Technical Specifications: Torque values, engine clearances, ignition timing settings, carburetor jet sizes, fluid capacities, recommended lubricants. Wiring Diagrams: Detailed electrical schematics for all factory-installed systems. Torque Specifications: Precise torque settings for critical fasteners (engine, chassis, wheels). Special Tool Requirements: Identification of any specialized tools needed for specific repair or maintenance tasks. Customization Notes: While primarily a repair manual, it may contain notes on performance tuning or variations. Technical Depth Depth: Comprehensive, covering everything from basic adjustments to full engine and transmission rebuilds, suitable for professional mechanics and experienced DIY enthusiasts. Diagnostic Charts: Troubleshooting guides based on symptoms to identify root causes of problems. Exploded Diagrams: Hundreds of detailed exploded views illustrating component relationships and assembly order. Rebuild Instructions: Step-by-step guides for complete engine, gearbox, and carburetor rebuilds. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely searchable text within the PDF, depending on the scan quality. Print Quality Printability: Printable pages (single or entire manual), high-resolution for clear diagrams and photos. Binding Type Binding Style: N/A (Digital Download) Paper Type Paper Quality For Print: N/A (Digital Download) - Recommended standard paper for printing. ⚙️ Engine Specifications Primary Engine Engine Type: Two-stroke, single-cylinder Displacement: 245.6 cc (approximate, common for OSSA 250 models) Bore X Stroke: Typical for OSSA 250: approx. 72mm x 60mm (exact figures will be in the manual) Cooling System: Air-cooled Performance Horsepower Range: Likely in...