🏷️ Basic Information

Make:

BMW

Model:

R90

Year:

1988

Internal Model Code:

R90/6 (likely reference, though R90 model designation is historical; 1988 production might refer to later variants like R100 models if R90 was phased out, but the manual explicitly states R90 1988)

👋 Introduction

Target Audience:

Owners of 1988 BMW R90 motorcycles undertaking maintenance, repair, or restoration; independent workshops specializing in vintage BMW motorcycles.

Value Proposition:

Provides comprehensive, in-depth technical information crucial for maintaining and repairing a classic BMW motorcycle, potentially saving significant costs compared to dealership service or less detailed manuals.

Manual Benefit:

Empowers owners with the knowledge to perform complex repairs and diagnostics, extending the lifespan and preserving the value of their vintage BMW R90.

📋 Manual Details

Manual Coverage:

Full Service, Repair, Rebuild, Refurbish, Restoration, Diagnostics

Page Count:

Detailed page count not specified, but described as 'very detailed' and containing 'everything'.

Manual Type:

Service and Repair Manual

Language:

English (assumed based on product description)

Format:

Digital (likely PDF, as is common for online sales of such manuals)

📖 Manual Coverage

Engine Systems:

Engine assembly, disassembly, internal components, valve adjustments, carburetor tuning and rebuilding, ignition system, lubrication, cooling system (air-cooled specific), exhaust system.

Transmission Systems:

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

Chassis Suspension Systems:

Front fork (BMW Telelever or Earles fork depending on specific R90 variant, though 1988 is unusual for R90), rear suspension (monoshock or twin shocks depending on model), swingarm, wheel bearing service, steering head bearing service.

Braking Systems:

Brake system overhaul, brake pad replacement, brake fluid flush and replacement, caliper service, master cylinder service.

Electrical Systems:

Wiring diagrams, component testing, battery maintenance, lighting system, charging system (alternator/generator), starter motor, horn, instrumentation.

Bodywork Frame:

Frame inspection, body panel removal and installation, fuel tank service, seat service, fairing (if applicable) repair.

Maintenance Procedures:

Oil changes, filter replacement, spark plug replacement, air filter cleaning/replacement, chain adjustment/lubrication (if applicable), brake fluid changes, battery care, general inspection routines.

Repair Procedures:

Engine rebuild (top and bottom end), transmission repair, carburetor synchronisation and rebuilding, electrical fault diagnosis, suspension component replacement, brake system overhaul.

Diagnostic Procedures:

Troubleshooting guides for common issues, engine performance diagnosis, electrical system fault finding, component testing methods.

Restoration Refurbishment:

Guidance on cleaning, painting, part sourcing, and reassembly for bringing a vintage BMW back to pristine condition.

Depth Of Coverage:

Comprehensive. Covers everything from basic maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures and electrical schematics. Suitable for both amateur mechanics and professional technicians.

📊 Manual Specifications

Digital File Type:

PDF (most probable format for digital sale)

Searchability:

Likely searchable text, allowing for quick keyword-based navigation.

Print Readability:

Designed for clear readability, with schematics and diagrams being a priority.

Binding:

N/A (Digital Format)

Paper Quality:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Air-cooled, four-stroke, boxer-twin engine (typical for BMW R-series)

Engine Displacement:

897cc (for R90/6 designation, the R90S had 897cc as well. Specific R90 model for 1988 might imply an R100 variant, but the manual explicitly states R90)

Horsepower:

Typically around 60-70 HP depending on specific R90 variant (e.g., R90/6 or R90S)

Torque:

Torque figures vary by model, typically in the 50-60 lb-ft range.

Carburetors:

Likely equipped with twin Bing carburetors (e.g., 32mm or 36mm depending on variant). Manual will detail their adjustment and rebuilding.

Fuel Type:

Unleaded gasoline (premium recommended for optimal performance and longevity).

🔧 Transmission

Transmission Type:

5-speed manual gearbox, shaft drive (cardan shaft)

Optional Gearbox:

N/A (standard for this era BMW R-series)

Clutch Type:

Dry single-plate clutch

Final Drive:

Shaft drive (maintenance and inspection procedures covered).

📐 Dimensions

Wheelbase:

Varies by model, typically around 1470mm (57.9 inches) for R90/6.

Dry Weight:

Approximately 200-220 kg (440-485 lbs) depending on specific R90 variant.

Fuel Tank Capacity:

Typically 24 liters (6.3 US gallons) for R90/6, R90S might differ.

🛡️ Safety Features

Crash Test Data:

N/A (Motorcycle safety ratings are not typically conducted in the same manner as automobiles).

Braking System Features:

Dual disc front brakes, single disc rear brake (standard on R90S, R90/6 may have disc rear or drum depending on market/spec). Manual will cover maintenance and repair of these.

Frame Construction:

Steel tube frame, known for stability and rigidity.

💡 Technology Features

Infotainment System:

N/A (This era of motorcycle pre-dates integrated infotainment systems as understood today. Focus is on mechanical and electrical functionality.)

Rider Assistance:

N/A (Focus is on core mechanical and electrical systems. ABS was not standard or common on R90 models, though it began appearing on BMWs later in the 80s.)

Connectivity Features:

N/A (No electronic connectivity features)

🔧 Maintenance

Oil Change Interval:

Typically every 5,000 km (3,000 miles) or annually, whichever comes first. Manual will provide precise interval.

Valve Adjustment Interval:

Recommended every 10,000 km (6,000 miles). Manual details the procedure.

Engine Oil Type:

SAE 20W/50 or SAE 15W/40 motorcycle-specific oil. Manual will specify exact BMW recommendations.

Gearbox Oil Type:

GL-5 80W/90 hypoid gear oil. Manual will confirm specific BMW part numbers or specifications.

Final Drive Oil Type:

GL-5 80W/90 hypoid gear oil. Manual will confirm specific BMW part numbers or specifications.

Brake Fluid Type:

DOT 4 or DOT 5.1 brake fluid. Manual will specify.

Common R90 Wear Items:

Carburetor diaphragm wear, output shaft seal leaks, valve seat wear, steering head bearing play, aging electrical connectors, swingarm bearing wear.

Manual Troubleshooting Coverage:

The manual is expected to provide detailed troubleshooting guides for these common issues and many others.

📚 Vehicle History

Bmw Motorcycle Legacy:

BMW has a long and prestigious history in motorcycle manufacturing, particularly renowned for its boxer-twin engines, shaft drive, and robust build quality, dating back to the early 20th century.

R90 Series Development:

The R90 series, including the R90/6 and R90S, was a significant step for BMW in the 1970s, offering more performance and refined styling compared to earlier models. The 1988 reference is unusual as the R90 series was largely superseded by R100 models by then. It might refer to a specific market variant or a manual covering R90s that were still in significant use or production in some form, or it could be a slight mislabeling of an R100 model manual.

Production Period:

R90 models were primarily produced from 1973 to 1976. The 1988 date suggests a potential for later model R100 manuals being described, or a manual focused on the enduring legacy of R90 engines/components in later models or extended production runs in specific markets.

🏆 Awards & Recognition

Historical Reputation:

The BMW R90 series, particularly the R90S, was highly regarded for its sporting prowess and touring capabilities, earning a reputation for being a premium, well-engineered motorcycle.

Owner Satisfaction:

Consistently high owner satisfaction for build quality, reliability, and riding experience, making them sought-after classics.

Manual Quality Certification:

N/A (Manuals are typically not certified, but quality is assessed by completeness and accuracy).