🏷️ Basic Information Identification Make: BMW Model: R80, R90, R100 Year: 1990 Codes Engine Code Family: M100/2 👋 Introduction Market Position Segment: Classic Airhead BMW Motorcycles Target User Base: Owners of BMW R80, R90, and R100 series motorcycles, particularly those manufactured around 1990. Also valuable for independent repair shops specializing in vintage BMWs. Competitive Analysis Manual Value: Provides indispensable, factory-level repair and maintenance data, crucial for preserving the functionality and value of these iconic motorcycles. Replaces or supplements less detailed informal guides. Key Features Authenticity: Represents professional-grade information trusted by mechanics worldwide for accurate repairs. Comprehensiveness: Covers a wide range of service, repair, and troubleshooting procedures. 📋 Manual Details Coverage Areas Manual Type: Service Repair Workshop Manual Language: English Format: Digital (PDF - inferred from common practice for this type of product, though not explicitly stated) Target Audience: Professional mechanics and experienced DIY enthusiasts 📖 Manual Coverage Systems Covered Engine Mechanical: Complete overhaul, component inspection, assembly, tuning, torque specifications Engine Electrical: Ignition system (points, electronic), charging system (alternator, regulator), starting system, wiring diagrams Fuel System: Carburetor overhaul (Bing), fuel tank, fuel lines, fuel pump (if applicable) Transmission Drivetrain: Gearbox disassembly and assembly, clutch operation, driveshaft maintenance, final drive unit Brakes: Hydraulic system (master cylinder, calipers, lines), brake pad replacement, bleeding procedures, drum brake adjustment (rear for some models) Suspension: Front fork (telescopic), rear swingarm, shock absorbers, wheel bearings Chassis Frame: Frame inspection, steering head bearing maintenance Electrical Components: Headlight, taillight, indicators, horn, battery, fuses Procedures Included Routine Maintenance: Oil changes, filter replacements, spark plug checks, valve clearance adjustment, lubrication points Troubleshooting: Diagnostic procedures for common performance issues, electrical faults, starting problems Rebuilding Overhaul: Detailed step-by-step guides for engine, transmission, and carburetor rebuilds Adjustments: Carburetor synchronization, idle speed, ignition timing, clutch, throttle cables Inspection Diagnosis: Wear limits for engine components, electrical system testing Technical Depth Diagnostic Capabilities: Advanced diagnostic procedures for identifying root causes of malfunctions Repair Complexity: Covers everything from basic fluid changes to complete engine and transmission rebuilds Documentation Type: Official factory-level service data, including exploded views, diagrams, and specifications 📊 Manual Specifications File Format Format Type: Digital (PDF) Searchability: Likely text-searchable if properly scanned and OCR'd, facilitating quick access to information Print Quality Image Clarity: High-resolution scans of original diagrams and photographs are essential for clarity Binding Type Binding Style: N/A (Digital format) Paper Type Paper Quality: N/A (Digital format) Completeness Coverage Scope: Comprehensive, covering all major mechanical and electrical systems relevant to the specified models and year ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, horizontally opposed boxer twin-cylinder Displacement R80: 797.5 cc (48.6 cu in) Displacement R90: 897.9 cc (54.8 cu in) Displacement R100: 980.7 cc (59.8 cu in) Bore Stroke R80: 82 mm x 75.6 mm (3.23 in x 2.98 in) Bore Stroke R90: 90 mm x 70.4 mm (3.54 in x 2.77 in) Bore Stroke R100: 94 mm x 70.4 mm (3.70 in x 2.77 in) Compression Ratio: Varies by specific model variant (e.g., R100RT, R100GS), typically around 8.5:1 to 9.5:1 Horsepower R80: Approx. 50-55 hp @ 6200 rpm (model dependent) Horsepower R100: Approx. 60-70 hp @ 7000 rpm (model dependent) Torque R100: Approx. 70-75 Nm @ 5000 rpm (model dependent) Fuel System Carburetors: Typically twin Bing Constant Velocity (CV) carburetors, e.g., Bing 32/40/42/45 depending on model and year Fuel Type: Unleaded gasoline, minimum 91 octane (RON+MON)/2 Ignition Ignition System: Contact breaker points ignition or early electronic ignition systems (depending on specific model variant within R100 range) Lubrication Oil Capacity: Approx. 3.0 - 3.5 liters (3.2 - 3.7 US qt) with filter change Oil Grade: API SG or higher, viscosity typically 20W-50 or 10W-40 depending on climate (refer to specific manual for exact recommendations) 🔧 Transmission Standard Gearbox Type: 5-speed, constant mesh, sequential manual gearbox Drive Type: Shaft drive to rear wheel Features Clutch Type: Single dry plate diaphragm spring clutch (operates from the right side of the engine) Gearbox Oil Grade: SAE 75W/90 or SAE 80W gear oil (API GL-4/GL-5) Gearbox Oil Capacity: Approx. 0.75 - 1.0 liter (0.79 - 1.05 US qt) 📐 Dimensions Exterior Wheelbase: Varies by model, typically around 1430 mm - 1510 mm (56.3 in - 59.4 in) Weights Dry Weight: Varies significantly by model (e.g., R80G/S, R100GS, R100RT), generally between 190 kg - 230 kg (419 lbs - 507 lbs) Gross Vehicle Weight Rating: Not typically specified in detail for motorcycles, but payload capacity is a consideration 🛡️ Safety Features Ratings Crash Test Data: N/A (Motorcycles not subjected to standardized automotive crash testing) Active Features Braking System: Dual disc front brakes (on most models), single disc rear brake (or drum on some earlier/smaller variants). Often with Brembo components. Passive Features Lighting: Halogen headlight, taillight, brake light, turn signals 💡 Technology Features Infotainment Infotainment System: N/A (Basic motorcycle of the era, no integrated infotainment systems) Driver Assistance ABS:...