1973-1976 BMW R90, R90S, R 90/6 Service Manual

BMW R90/S/6 1973–1976 Workshop Documentation

• Covers 1973–1976 BMW R60/6, R75/6, R90/6, and R90S motorcycles, documenting engine, fuel system, electrical, and gearbox specifications
• Original OEM publication 11 00 999 421
• Contains 80+ pages of detailed technical diagrams, torque tables, component exploded views, and fault-finding charts
• Downloads to your account within seconds of checkout
• Permanent availability in your purchase account — no re-buy required
• Laid out for standard letter and A4 printing
• Indexed PDF search covers every chapter and appendix
• This technical publication is the standard reference used for the R-series Boxer engines, capturing the factory-specified tolerances and assembly patterns for the 1973–1976 production run

Engine and Component Documentation

The 1973–1976 BMW R90/S/6 service manual provides technical data for the Boxer engine range, including R60/6, R75/6, R90/6, and R90S models. The contents detail engine internal clearances, crankshaft and connecting rod bearing tolerances, cylinder boring and honing specifications, and oil pump design parameters. Electrical system documentation includes Bosch starter and alternator testing, contact breaker point settings, and ignition timing procedures.

Fuel system information covers Bing and Dellorto carburetor configurations, including jet sizing and float level adjustments. Gearbox specifications detail internal ratios and shim-adjusted axial float settings for the 5-speed transmission. The manual also includes how factory workshop documentation is structured for these air-cooled units.

Technical Data Highlights

Engine lubrication pressure warning lamps are specified at 0.2–0.5 atmg. Cylinder head bolt torque for the R90 series is documented across three stages. Valve clearance for the intake is listed at 0.15 mm in the cylinder head specification table. Piston ring gap for the top compression ring is specified at 0.30–0.45 mm for R90 models. The R90S fuel tank capacity is documented at 24 liters including reserve. All service data shown here is for reference only — qualified technicians and the original OEM documentation remain the authoritative source for any hands-on work.

An official BMW factory workshop manual covering the 1973–1976 R60/6, R75/6, R90/6, and R90S, documenting engine, chassis, electrical, and fuel-injection specifications for the classic air-cooled Boxer motorcycle series.

Document Reference: 11 00 999 421, Published by Bayerische Motoren Werke AG