The 1971 debut of the FX Super Glide marked a pivotal moment in motorcycling history; it was the industry's first 'Factory Custom.' Designed by Willie G. Davidson, the FX-74 successfully married the massive chassis of the FL Electra Glide with the nimble telescopic forks of the XL Sportster, creating a hybrid that defined the cruiser aesthetic for decades to come.
| Component | Specification |
|---|---|
| Production Years | 1971-1980 |
| Engine Type | Shovelhead V-Twin (1200cc / 74ci) |
| Oil Capacity | 3.8 Liters |
| Tire Size (Front) | 100/90-19 |
| Tire Size (Rear) | 130/90-16 |
| Spark Plug | H-D 5R6A |
| Battery | YB16-B |
Technical Deep Dive: The Shovelhead Legacy
The heart of the FX-74 is the 1200cc Shovelhead engine. Characterized by its rocker covers resembling inverted coal shovels, this powerplant delivered the low-end torque essential for the 'Super Glide' experience. Unlike modern units, the Shovelhead requires meticulous thermal management. Its aluminum heads and iron cylinders have different expansion rates, making oil selection and warm-up cycles critical for gasket longevity.
Maintenance Guidelines
Lubrication System
The FX 1200 utilizes a dry-sump lubrication system with a 3.8L capacity. Because these engines rely heavily on oil for cooling, viscosity must be matched to the ambient operating temperature:
- SAE 50: Standard for temperatures above 60°F.
- SAE 60: Recommended for heavy-duty use in temperatures exceeding 80°F.
- 20W-50: Suitable for colder climates (below 40°F).
Chassis and Tires
The '74' series setup uses a 19-inch front wheel for stability and a 16-inch rear for that classic cruiser profile. Proper inflation is vital for handling the 1200's weight. Maintain 1.8 bar (26 psi) in the front and 1.8 to 2.1 bar (26-30 psi) in the rear depending on whether you are carrying a passenger or luggage.
Electrical and Ignition
The FX series from this era utilizes the YB16-B battery. Given the vibration inherent in the Shovelhead design, ensure battery terminals are checked every 2,500 miles. For combustion, the H-D 5R6A spark plug remains the gold standard for maintaining the correct heat range in the 74-cubic-inch combustion chambers.
Editor’s Verdict
The FX 1200 (FX-74) is more than a motorcycle; it is a mechanical artifact. While it requires more 'hands-on' maintenance than a modern Twin Cam or Milwaukee-Eight, the reward is a visceral, unfiltered connection to the road that few modern machines can replicate. For the collector or the dedicated enthusiast, it remains the definitive Harley-Davidson.