🏷️ Basic Information

Make:

BMW

Model:

R90

Year:

1990

Manual Product Name:

BMW R90 1990 Repair Service Manual

Manual Description:

BMW R90 1990 Repair Service Manual-Service Manual Repair PDF Download. The manual for BMW R90 1990 is available for instant download and been prepared primarily for professional technicians. However, adequate data is given for the majority...

👋 Introduction

Niche:

Specialized service manual for a specific model of classic BMW motorcycle.

Value Proposition:

Provides essential, detailed information for maintaining and repairing a sought-after vintage BMW motorcycle.

Target Audience:

Professional motorcycle technicians and experienced DIY enthusiasts.

Content Focus:

Practical, actionable repair and maintenance guidance.

📋 Manual Details

Primary Coverage:

Repair and service procedures for the BMW R90 motorcycle.

Secondary Coverage:

Maintenance schedules, troubleshooting, diagnostics, and technical specifications.

Estimated Page Count:

Approximately 300-500 pages (typical for comprehensive motorcycle service manuals of this era, exact count not specified in product info).

Type:

Service and Repair Manual

Language:

English

Format:

PDF (Digital Download)

📖 Manual Coverage

Engine Mechanical:

Complete engine disassembly, inspection, reassembly, including cylinder head, pistons, crankshaft, camshaft, valve train, timing.

Fuel System:

Carburetor tuning, cleaning, and overhaul (likely Bing carburetors), fuel pump, fuel lines, fuel tank maintenance.

Ignition System:

Spark plugs, ignition coils, points, condensers (if applicable for the 1990 model), timing adjustments, troubleshooting.

Transmission And Drivetrain:

Gearbox disassembly, inspection, repair, clutch operation and adjustment, final drive maintenance (shaft drive).

Brakes:

Hydraulic brake system service, caliper overhaul, master cylinder repair, fluid replacement, pad/shoe replacement, disc/drum inspection.

Suspension And Steering:

Front fork service (oil changes, seal replacement), rear shock absorber maintenance, steering head bearing adjustment and replacement.

Electrical System:

Wiring diagrams, component testing (battery, starter, alternator, lighting, horn), fuses, relays, switches.

Chassis And Bodywork:

Frame inspection, fairing/body panel removal and installation, seat, luggage rack, and accessory mounting.

Routine Maintenance:

Oil changes, filter replacements, chain/shaft drive lubrication, spark plug checks, tire pressure checks.

Troubleshooting:

Systematic diagnostic procedures for common and uncommon problems, symptom-based troubleshooting guides.

Repair And Overhaul:

Detailed step-by-step instructions for major component repairs and complete overhauls.

Adjustments:

Carburetor synchronization, valve clearance adjustment, clutch and brake lever free play, steering head bearing preload.

Torque Specifications:

Accurate torque values for all critical fasteners.

Depth:

Comprehensive, suitable for professional technicians, with adequate data for advanced DIY mechanics.

Diagnostic Capabilities:

Includes diagnostic flowcharts and specific tests for electrical and mechanical components.

📊 Manual Specifications

Quality:

High-resolution, searchable PDF with clear text and images.

Searchability:

Likely text-searchable due to PDF format.

Printability:

Designed for printing, with standard page layouts.

Digital Format Advantage:

Instant download and accessible on multiple devices, no physical binding required.

Digital Simulation:

Simulates a professionally printed manual with clear diagrams and illustrations.

⚙️ Engine Specifications

Engine Type:

Air-cooled, four-stroke boxer twin

Displacement:

900cc (approximate, specific model variants may exist)

Bore X Stroke:

Typically around 83mm x 83mm for R90/6 variants, precise figures in manual.

Compression Ratio:

Typically around 8.5:1 to 9.5:1, manual will specify.

Horsepower:

Approximately 50-65 HP, manual will provide exact figures for the specific model variant.

Torque:

Around 70-75 Nm, manual will provide exact figures.

Carburetors:

Dual Bing carburetors (e.g., 32mm or 40mm, depending on model variant).

Fuel Type:

Unleaded gasoline (91 octane or higher recommended, manual will confirm).

Oil Type:

Typically SAE 20W-50 or SAE 15W-40 motorcycle-specific mineral or synthetic oil. Manual to confirm exact BMW specification.

Oil Capacity:

Approximately 2.5 - 3.0 liters with filter change, manual to confirm.

🔧 Transmission

Type:

Constant mesh, 5-speed manual gearbox

Availability:

Not applicable, 5-speed was standard.

Drive Type:

Shaft drive (enclosed driveshaft)

Clutch Type:

Dry single-plate or multi-plate clutch (depending on specific R90 variant, manual will clarify).

Transmission Fluid Type:

Typically gear oil for the gearbox and final drive. Manual to confirm SAE viscosity and API rating.

📐 Dimensions

Wheelbase:

Variable depending on exact model (e.g., R90/6 ~1460mm), manual to confirm.

Seat Height:

Variable, manual to confirm specific model height.

Dry Weight:

Around 200-220 kg, manual to confirm exact figures for different configurations.

Gross Vehicle Weight Rating:

Manual will specify maximum permissible weight.

🛡️ Safety Features

Crash Test Information:

Not applicable for motorcycles of this era in the same way as cars.

Braking System:

Dual disc front brakes, single disc or drum rear brake (depending on model variant). Manual provides detailed specs.

Lighting System:

Headlight, taillight, brake lights, turn signals.

Frame Construction:

Steel tube frame designed for stability and handling.

💡 Technology Features

System Type:

Not applicable (basic analog instrumentation).

Features:

None (motorcycle of its era).

Features:

None.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 km or annually. Manual will specify exact intervals.

Valve Clearance Check:

Typically every 6,000-10,000 km. Manual is critical for this procedure.

Shaft Drive Maintenance:

Lubrication and inspection at specified intervals. Manual details procedures and grease types.

Brake Fluid:

DOT 3 or DOT 4 hydraulic fluid, manual will confirm specific type and replacement interval.

Fork Oil:

Specific viscosity and quantity, e.g., SAE 15W or SAE 20W. Manual to specify exact type and amount.

General Wear And Tear:

Common issues on bikes of this age include aging electrical components, worn fork seals, carburation issues, and potential clutch wear.

Ignition Points:

Points and condensers require periodic adjustment and replacement for optimal performance.

Oil Leaks:

Older boxer twins can be prone to minor oil leaks from gaskets and seals, which the manual helps address.

📚 Vehicle History

Bmw Motorcycles Legacy:

BMW has a long and storied history in motorcycle manufacturing, known for engineering excellence, reliability, and innovation since the early 20th century.

R90 Lineage:

The R90 models (R90/6 and R90S) were introduced in the mid-1970s and represented a significant step in BMW's boxer twin motorcycle development, offering larger displacement and improved performance over previous models. The 1990 mention in the product name might be an error or refer to later models that share lineage/parts, but the R90 series itself was primarily a 70s phenomenon. The manual likely covers the R90/6 and R90S from their original production years.

Production Years:

R90/6 and R90S were produced from 1973 to 1976. The 1990 date in the product title may refer to a later interpretation or a manual that also covers subsequent models with similar engine configurations, but the core R90 models predate 1990.

Manufacturing Location:

Berlin, Germany (BMW Motorrad plant)

🏆 Awards & Recognition

Model Reputation:

The R90 series, particularly the R90S, is highly regarded for its performance, build quality, and handling for its time, often winning critical acclaim and praised by riders.

Critical Reviews:

Contemporary reviews highlighted its smooth power delivery, solid handling, and touring capability. The R90S was particularly noted for its sportier performance and styling.

Manual Accuracy:

Prepared primarily for professional technicians, implying a high degree of accuracy and adherence to factory specifications.