| Component | Specification |
|---|---|
| Engine Type | 49cc Air-cooled 4-stroke OHC Single |
| Engine Oil | SAE 10W-30 (0.7 L Refill / 0.8 L Total) |
| Tire Size | Front & Rear: 3.50-10 4PR |
| Battery | 6N4-2A-4 (6-Volt System) |
| Spark Plug | NGK C7HSA (Gap: 0.6mm – 0.7mm) |
The Honda ST 50 G DAX, specifically the ST50 and ST50G variants produced between 1970 and 1980, remains a masterclass in minimalist industrial design. A unique engineering highlight of this model is its monocoque “T-bone” pressed-steel frame. Unlike traditional tubular frames, this design integrated the fuel tank directly inside the chassis, lowering the center of gravity while providing a distinct aesthetic silhouette that earned it the nickname “Dachshund” (Dax).
Engineering Overview
From a technical perspective, the ST 50 G is powered by Honda’s legendary horizontal OHC engine. This powerplant is renowned for its thermal efficiency and longevity. The ‘G’ designation often denotes specific regional equipment, such as the inclusion of indicators or specific lighting configurations required for the German or European markets during the 1970s. The 6-volt electrical system, though modest by modern standards, is highly reliable if the 6N4-2A-4 battery is properly maintained.
Maintenance Specifications
Lubrication System
For optimal engine protection, MotoSpecsLab recommends SAE 10W-30 motor oil meeting API SE standards or higher. During a standard oil change (drain and refill), the engine requires 0.7 liters. If the engine has been completely disassembled, the total capacity is 0.8 liters. Regular oil changes are critical as these engines rely solely on splash lubrication and a small internal screen rather than a modern spin-on filter.
Chassis and Tires
The Dax utilizes 10-inch wheels which contribute to its nimble handling. Both front and rear tires are sized at 3.50-10 4PR. Maintaining correct tire pressure is vital for rim protection and handling stability:
- Front: 1.25 bar (18 psi)
- Rear (Solo): 1.50 bar (21 psi)
- Rear (With Passenger): 2.0 bar (28 psi)
Ignition System
To ensure consistent combustion and easy cold starts, the NGK C7HSA spark plug is the factory standard. The electrode gap must be precisely set between 0.6mm and 0.7mm. A fouled plug or incorrect gap on the 6V ignition system can lead to significant power loss and difficult starting.
Editorial Verdict
The Honda ST 50 G DAX is more than a pit bike; it is a collectible piece of engineering history. Its simplicity makes it an ideal candidate for DIY maintenance, provided the owner adheres to the strict 6V electrical requirements and frequent oil service intervals. Its durability is a testament to Honda’s 1970s build quality, often outlasting the very machines meant to replace it.