🏷️ Basic Information

Make:

BMW

Model:

R80, R90, R100 Series

Year:

1985

Chassis Codes:

R80/7, R90S, R100/7, R100RS, R100RT, R100CS, R100GS (early models), R100R (early models)

Engine Codes:

Type 247 (Airhead Boxer Twin)

👋 Introduction

Market Position:

Essential documentation for owners and mechanics of classic BMW airhead motorcycles, supporting models that defined a generation of touring and everyday motorcycling.

Competitive Analysis:

This factory manual provides the highest level of accuracy and detail compared to aftermarket manuals, covering all variations and technical nuances specific to BMW's engineering for these models.

Key Features:

Official factory content, comprehensive coverage, detailed diagrams, troubleshooting guides, printable format.

Target Audience:

BMW motorcycle owners, independent repair shops, motorcycle restoration specialists.

📋 Manual Details

Coverage Areas:

All major mechanical, electrical, and bodywork components for the specified models.

Page Count:

Hundreds of pages (specific count not provided but implied to be comprehensive).

Manual Type:

Factory Service Repair Manual (FSM)

Language:

English (implied by product description and target market)

Format:

Downloadable PDF

📖 Manual Coverage

Engine:

Engine teardown, reassembly, component inspection, tuning, lubrication, cooling system.

Transmission:

Gearbox disassembly, reassembly, clutch service, final drive inspection and repair.

Electrical:

Ignition system, charging system, lighting, wiring diagrams, starter motor, battery service.

Brakes:

Brake system overhaul, fluid replacement, caliper service, master cylinder.

Suspension:

Front fork (telescopic and possibly Monolever for later models if applicable to '85), rear shock absorber service, swingarm.

Chassis Bodywork:

Frame inspection, body panel removal and installation, seat, fuel tank, fairings (if equipped).

Wheels Tires:

Wheel bearing service, spoke tensioning, tire replacement, rim inspection.

Maintenance:

Scheduled maintenance tasks, oil changes, filter replacements, valve adjustments, spark plug replacement.

Troubleshooting:

Diagnostic procedures for common mechanical and electrical faults.

Repair:

Step-by-step instructions for component disassembly, repair, and reassembly.

Technical Specifications:

Torque values, clearances, fluid capacities, electrical specifications.

Rebuilds:

Detailed procedures for engine and gearbox rebuilds.

Technical Depth:

Comprehensive, from basic maintenance to complete engine and transmission overhauls.

Diagnostic Procedures:

In-depth diagnostic trees and fault-finding guides.

Wiring Diagrams:

Detailed, color-coded (if original) electrical schematics.

📊 Manual Specifications

File Format:

PDF

Searchable Text:

Typically yes for factory PDFs, enabling quick access to information.

Print Quality:

High resolution, allowing for clear printing of diagrams and text.

Binding Type:

N/A (Downloadable PDF - user dependent for physical binding).

Paper Type:

N/A (Downloadable PDF - user dependent for physical printing).

⚙️ Engine Specifications

Engine Type:

Air-cooled, horizontally opposed twin-cylinder boxer engine.

Bore X Stroke:

R80: 82mm x 74.6mm; R90/6 & R90S: 90mm x 70.6mm; R100: 94mm x 70.6mm

Displacement:

R80: 797.5cc; R90/6 & R90S: 897.9cc; R100: 979.7cc

Compression Ratio:

Varies by model and year, typically 8.5:1 to 9.5:1

Horsepower:

R80: ~50 hp; R90S: ~65 hp; R100/7: ~60 hp; R100RS/RT: ~70 hp

Torque:

Specific values vary, but indicative of strong low-to-mid range torque delivery.

Carburetors:

Typically Bing constant-velocity (CV) carburetors. R80: 32mm; R90S: 32mm or 40mm Dell'Orto (S model); R100 series: 32mm or 40mm

Fuel Type:

Unleaded gasoline (from 1985 onwards, premium unleaded typically recommended due to compression ratios).

Valves:

2 valves per cylinder, pushrod operated overhead valves (OHV).

🔧 Transmission

Transmission Type:

5-speed constant mesh gearbox.

Clutch:

Dry single-plate clutch (except early R90S with wet clutch).

Drive Type:

Shaft drive to rear wheel.

Gear Ratios:

Specific ratios vary by model and are detailed within the manual.

Gearbox Oil Type:

Typically SAE 80W/90 hypoid gear oil.

📐 Dimensions

Wheelbase:

Varies by model, approximately 1460-1500 mm.

Seat Height:

Varies by model and suspension, typically around 780-820 mm.

Dry Weight:

Varies significantly by model, generally 190-220 kg.

Gross Vehicle Weight Rating:

Typically around 350-380 kg.

Luggage Options:

Many models were equipped with factory luggage racks and optional panniers/top cases; manual covers mounting and service.

🛡️ Safety Features

Safety Ratings:

N/A (Motorcycles are not typically subjected to formal crash test ratings like cars).

Brakes:

Front: Dual Disc Brake (R100RS/RT, R90S) or Single Disc Brake (R80/7, R100/7). Rear: Single Disc Brake (most models) or Drum Brake (early models).

Suspension Features:

Anti-dive mechanisms on some front forks (e.g., Earles fork variants, early Monolever systems) for improved braking stability.

Lighting:

Halogen headlight, taillight, brake light, turn signals.

Frame Construction:

Robust tubular steel frame designed for stability and durability.

💡 Technology Features

Infotainment System:

Not applicable; these are classic motorcycles focused on core motorcycling experience.

Driver Assistance Features:

Not applicable; focus is on rider input and mechanical feedback.

Connectivity Options:

Not applicable.

Ignition Type:

Battery-coil ignition, often with breaker points or early electronic ignition systems.

Headlight Type:

Halogen sealed beam units, size and wattage varies by model.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000 - 7,500 km or annually, whichever comes first.

Valve Adjustment Interval:

Every 10,000 - 15,000 km, due to the robust nature of the OHV design.

Major Service Interval:

Comprehensive checks and potential replacements at higher mileages, detailed in manual.

Engine Oil Type:

SAE 20W-50 or SAE 15W-40 motorcycle-specific mineral or semi-synthetic oil is commonly recommended. Refer to manual for exact viscosity by temperature.

Engine Oil Capacity:

Approximately 2.5 - 3.0 liters (depending on filter replacement).

Brake Fluid Type:

DOT 4 or DOT 5.1 (depending on system, check manual for specifics).

Final Drive Oil Type:

SAE 80W-90 hypoid gear oil.

Known Issues:

Common areas include clutch wear, output shaft seal leaks, swingarm bearings, and alternator brushes. The manual provides diagnostic steps for these.

Carburetor Synchronization:

Requires periodic synchronization for smooth running, detailed procedure in manual.

Common Part Numbers:

Specific part numbers for filters, spark plugs, and common wear items are listed within the manual.

📚 Vehicle History

Brand Heritage:

BMW Motorrad has a long history of engineering excellence, particularly with its boxer engine platform, known for reliability, durability, and touring capability.

Model Evolution:

These models represent the evolution of BMW's successful '7' series and the introduction of the R100 line, building on the legacy of earlier boxer twins. The 1985 model year often included updates and refinements, and was a transition year for some technologies like the Monolever rear suspension on certain models.

Production Years:

The 'Airhead' boxer series spanned from the late 1960s through the mid-1990s. The R80, R90, and R100 models were produced throughout the 1970s and 1980s, with the 1985 models being a significant iteration.

Manufacturing Location:

Berlin, Germany (BMW Motorrad plant).

🏆 Awards & Recognition

Recognitions:

BMW 'Airhead' motorcycles are widely recognized for their longevity, reliability, and ability to cover vast distances, making them classics and highly sought after for touring and adventure riding.

Owner Satisfaction:

Consistently high owner satisfaction ratings among enthusiasts for their robustness and character.

Certifications:

N/A (As a service manual, it is a product of BMW's internal engineering standards).