A hallmark of post-war German engineering, the BMW R 67/2/3 remains a pinnacle of the 600cc boxer lineage. A unique engineering highlight of this specific series was its transition to a 28 hp output, making it one of the most powerful and reliable sidecar-capable motorcycles of the early 1950s. Unlike its predecessors, the R 67/2/3 featured improved cylinder head cooling and a refined gearbox, cementing its reputation as a ‘workhorse’ for the long-distance touring elite.
| Feature | Specification |
|---|---|
| Production Years | 1952–1956 |
| Engine Type | Opposed Twin (Boxer) |
| Oil Type | SAE 40 (Summer) / SAE 20 (Winter) |
| Oil Capacity | 2.0 Liters |
| Tire Size (F/R) | 3.50 x 19 / 3.50 x 19 |
| Spark Plug | Bosch W 4 AC (NGK B7HS) |
| Battery | BAE 6/8 |
Engineering Legacy & Performance Analysis
The BMW R 67/2/3 – 0267 represents the apex of the plunger-frame era. Its 594cc overhead-valve (OHV) engine was designed for sustained torque, crucial for handling the weight of heavy Steib sidecars. The ‘0267’ designation refers to its internal project evolution, showcasing BMW’s commitment to incremental mechanical perfection. The chassis stability, provided by the telescopic front forks and plunger rear suspension, offered a level of comfort that was virtually unmatched in the mid-century market.
Maintenance Protocol
Lubrication System
To maintain the integrity of the boxer engine, lubrication is paramount. The system requires 2.0 liters of high-quality mineral oil. In temperate or summer conditions, SAE 40 is mandatory to ensure film strength at high operating temperatures. For winter operation, SAE 20 provides the necessary flow during cold starts.
Wheel & Tire Management
The R 67/2/3 utilizes a symmetrical 19-inch wheel setup. Maintaining correct pressures is vital for handling predictability, especially given the plunger rear suspension’s characteristics.
- Front: 1.2 bar (17.4 psi)
- Rear: 1.5 bar (21.7 psi)
Note: If a sidecar is attached, rear pressures should be increased significantly to compensate for the lateral load.
Electrical & Ignition
The 6V electrical system relies on the BAE 6/8 battery. For optimal combustion, the Bosch W 4 AC (modern equivalent: NGK B7HS) is recommended. Ensure the electrode gap is checked every 3,000 miles to prevent misfires and carbon fouling.
Frequently Asked Questions
What is the oil capacity for the BMW R 67/2/3?
The engine requires exactly 2.0 liters of oil for a complete refill.
Which spark plug should I use for modern fuel?
While the original spec is Bosch W 4 AC, the NGK B7HS is an excellent modern alternative that handles contemporary unleaded fuels well.