🏷️ Basic Information Identification Make: BMW Model: R90 Year: 1984 Codes Model Code Series: R90 Series 👋 Introduction Market Position Target Audience: BMW motorcycle enthusiasts, DIY mechanics, restoration specialists, service technicians Competitive Analysis Value Proposition: Provides essential technical data and procedural guidance for maintaining and repairing the iconic BMW R90, empowering owners to perform their own work with confidence and precision. Key Features User Benefit 1: Detailed step-by-step repair instructions User Benefit 2: Comprehensive diagnostic flowcharts User Benefit 3: Essential technical specifications and torque values User Benefit 4: Clear, easy-to-understand language and diagrams User Benefit 5: Enables cost savings by facilitating DIY repairs 📋 Manual Details Coverage Areas Primary Coverage: Complete Service and Repair Secondary Coverage: Troubleshooting and Diagnostics Page Count Estimated Page Count: 300+ Manual Type Type: Service Manual / Repair Manual Language Language: English Format Format: Downloadable Digital File (PDF) 📖 Manual Coverage Systems Covered Engine: Full overhaul, tuning, carburetion, ignition system Transmission: Gearbox disassembly, assembly, lubrication, clutch service Drivetrain: Shaft drive, final drive, universal joints Suspension: Front forks, rear shock absorbers, linkage adjustments Brakes: Hydraulic system, caliper service, disc and pad replacement Electrical System: Wiring diagrams, battery, charging system, lighting, ignition troubleshooting Fuel System: Fuel tank, fuel lines, fuel pump, carburettor tuning Cooling System: Air-cooled engine specifics, oil circulation Bodywork And Frame: Chassis inspection, body panel removal and installation Controls: Throttle, clutch, brake levers, foot controls Procedures Included Preventative Maintenance: Scheduled servicing, fluid changes, filter replacements, chain adjustment Troubleshooting: Step-by-step diagnostic guides for common and uncommon issues Repair And Rebuild: Detailed instructions for component disassembly, repair, and reassembly Adjustments: Valve clearance, carburetor synchronization, ignition timing Electrical Diagnostics: Component testing, fault finding for electrical systems Specification Setting: Torque values, clearances, fluid levels Body Panel Repair: Instructions for minor bodywork repairs and panel alignment Technical Depth Depth: Comprehensive: Covers everything from basic maintenance to full engine and transmission rebuilds, including advanced diagnostics. Engine Rebuild: Detailed steps for full engine overhaul, including piston, ring, bearing, and cylinder replacement. Transmission Rebuild: In-depth guidance for gearbox disassembly, inspection of gears and shafts, and reassembly. Electrical Diagnostics Level: Advanced diagnostics for electrical faults, including troubleshooting wiring harness issues and component testing. 📊 Manual Specifications File Format Compatibility: Compatible with all PDF readers (Adobe Reader, Foxit, etc.) Print Quality Resolution: High-resolution scans suitable for printing and digital viewing Binding Type Binding: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) Searchability Text Searchability: Fully searchable text for quick information retrieval ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, boxer-twin cylinder Displacement: 897 cc Bore X Stroke: 90 mm x 70.6 mm Compression Ratio: 9.5:1 Horsepower Max: 60 hp (44 kW) at 6,250 rpm Torque Max: 70 Nm (52 lb-ft) at 5,000 rpm Valve Adjustment Method: Screw and locknut adjustment Fuel System Carburetors: 2 x Bing 32mm (Type 54/40/101 or similar) Fuel Type: Unleaded gasoline, minimum 91 octane (RON+MON)/2 Ignition System Type: Battery-coil, distributor ignition (or electronic ignition for some variants) Lubrication System: Wet sump Valve Train Configuration: Overhead valves (OHV), pushrod actuated 🔧 Transmission Standard Type: 5-speed manual gearbox Clutch: Single dry plate, diaphragm spring Features Drivetrain: Shaft drive to rear wheel Gear Ratios Final Drive: Approx. 3.36:1 (11/37 teeth) Fluid Type Gearbox Oil: SAE 80W/90 Hypoid Gear Oil (API GL-5) Fluid Capacity Gearbox Oil Capacity: Approx. 1.3 liters (1.4 US qt) 📐 Dimensions Exterior Wheelbase: Approx. 1465 mm (57.7 inches) Length: Approx. 2180 mm (85.8 inches) Width: Approx. 800 mm (31.5 inches) Weights Dry Weight: Approx. 205 kg (452 lbs) Gross Vehicle Weight: Approx. 400 kg (882 lbs) 🛡️ Safety Features Ratings Safety Standards: Designed to meet contemporary safety regulations for motorcycles Active Features Braking System: Dual front disc brakes, single rear disc brake Suspension Stability: Telescopic front forks, BMW Motorrad swing arm with adjustable rear shocks for improved handling and stability Passive Features Frame Construction: Robust steel tube frame for structural integrity 💡 Technology Features Infotainment Infotainment System: N/A (Classic era motorcycle, focus on mechanical systems) Driver Assistance Driver Assistance Features: N/A (Classic era motorcycle) Connectivity Connectivity Features: N/A (Classic era motorcycle) Lighting Headlight Type: Halogen (standard) 🔧 Maintenance Service Intervals Oil Change Interval: Every 5,000 km (3,000 miles) or annually Valve Adjustment Interval: Every 10,000 km (6,000 miles) Spark Plug Replacement Interval: Every 10,000 km (6,000 miles) Fluid Specifications Engine Oil Type: SAE 20W-50 Motorcycle Oil (Mineral or Synthetic) Engine Oil Capacity: Approx. 2.5 liters (2.6 US qt) Brake Fluid Type: DOT 4 Hydraulic Brake Fluid Known Issues Common Issue 1: Carburetor synchronization drift Common Issue 2: Wear in final drive splines Common Issue 3: Leaking fork seals Common Issue 4: Aging electrical connectors and wiring insulation 📚 Vehicle History Brand Heritage Manufacturer: Bayerische Motoren Werke AG (BMW) Motorcycle Division History: BMW has a long and storied history in motorcycle manufacturing, dating back to the early 20th century, renowned...