| Specification | Value |
|---|---|
| Engine | High Output Twin Cam 103 (1690cc) |
| Emissions Standard | Euro 4 |
| Engine Oil | H-D 360 20W50 (2.8 Liters) |
| Tire Size (Front/Rear) | 130/90B16 / 180/70B16 |
| Spark Plug | HD 6R12 (0.97-1.09 mm gap) |
| Battery | 65989-97D |
The End of an Era: Engineering Highlight
The 2017 Harley-Davidson Dyna Fat Bob (FXDF) holds a significant place in motorcycling history as the final iteration of the Dyna platform before its controversial merger into the Softail line in 2018. This specific ‘Euro 4’ variant represents the pinnacle of Twin Cam engineering, featuring refined fuel mapping and exhaust sensors designed to meet stringent European emission standards without sacrificing the raw, mechanical character that defined the Dyna’s rubber-mounted engine chassis.
Performance and Powertrain
At the heart of the FXDF/17 is the High Output Twin Cam 103 engine. Delivering substantial low-end torque, the power is managed through a 6-speed Cruise Drive transmission. The Euro 4 configuration includes an optimized catalytic converter system integrated into the signature ‘Tommy Gun’ 2-1-2 exhaust, ensuring environmental compliance while maintaining the aggressive aesthetic the Fat Bob is known for.
Maintenance Specifications & Fluids
To maintain peak performance and longevity of the FXDF/17, adhering to the following technical specifications is mandatory:
- Engine Lubrication: Use 2.8 liters of Harley-Davidson 360 20W50. For extreme temperature variations, synthetic alternatives meeting H-D standards are acceptable.
- Ignition System: Utilize HD 6R12 spark plugs. The gap must be precisely set between 0.97 mm and 1.09 mm to ensure efficient combustion and prevent misfires under high load.
- Electrical: The 65989-97D battery provides the high cold-cranking amps (CCA) required to turn over the 103 cubic inch V-twin.
Chassis and Handling
The Fat Bob is distinguished by its beefy front end and dual disc brakes. Proper tire maintenance is critical for the handling characteristics of this 320kg machine:
- Front Tire: 130/90B16 67H, inflated to 2.48 bar (36 psi).
- Rear Tire: 180/70B16 77H, inflated to 2.76 bar (40 psi).
Regularly inspect the dual front rotors and four-piston calipers, as the FXDF’s weight and performance profile demand significant stopping power.
Technical FAQ
What is the correct spark plug gap for the 2017 Fat Bob?
The HD 6R12 spark plugs should be gapped to 0.97-1.09 mm (0.038-0.043 inches).
How much oil does the FXDF/17 require for a standard change?
A standard oil and filter change requires approximately 2.8 liters (approx. 3.0 US quarts) of 20W50 motorcycle oil.
Is this model compatible with the new Softail parts?
No. The 2017 FXDF uses the Dyna frame with twin external rear shocks, whereas 2018+ models use the mono-shock Softail frame. Most chassis and exhaust components are not interchangeable.