| Specification | Data |
|---|---|
| Model / Year | FLHR / 2007 |
| Engine Type | Twin Cam 96 (1584cc) |
| Oil Grade & Capacity | 20W-50 / 3.8 L (4.0 US qt) |
| Tire Size (Front) | MT90B16 72H |
| Tire Size (Rear) | MU85B16 77H |
| Battery Type | 66010-97C |
| Spark Plug | 6R12 |
The 2007 Harley-Davidson Road King (FLHR) marks one of the most significant engineering milestones in the history of the Touring family. It was the inaugural year for the Twin Cam 96™ engine and the 6-Speed Cruise Drive™ transmission, a combination that fundamentally solved the high-RPM highway vibration issues found in earlier 88-cubic-inch models.
Engineering Evolution: The 1584cc Powerplant
Moving from the 1450cc (88ci) to the 1584cc (96ci) engine wasn’t just a bore and stroke increase. The 2007 FLHR introduced an Electronic Sequential Port Fuel Injection (ESPFI) system as standard, eliminating the carburetor option entirely. This setup, paired with the new 6-speed gearbox, provided a 17% increase in peak torque over its predecessor, making the Road King a true long-distance powerhouse.
Maintenance & Service Fundamentals
For the professional technician or the dedicated owner, maintaining the FLHR/07 requires adherence to specific fluid and electrical tolerances:
- Lubrication: The Twin Cam 96 thrives on high-quality 20W-50 synthetic or mineral oil. A full dry-fill requires 3.8 liters. MotoSpecsLab recommends checking primary and transmission fluids concurrently with engine oil changes.
- Ignition: The 6R12 spark plugs are essential for maintaining the correct heat range in the air-cooled V-Twin environment.
- Electrical: The 66010-97C battery is a high-CCA unit designed to handle the increased compression of the 96ci engine. Ensure terminal connections are torqued to prevent vibration-induced starting issues.
Chassis & Tire Dynamics
The 2007 frame retains the classic touring geometry but requires precise tire pressure management to avoid the notorious “bagger wobble.” The front MT90B16 should be maintained strictly at 36 psi. The rear MU85B16 allows for variability: 36 psi for solo cruising, increasing to 40 psi when the hard saddlebags are loaded for touring.
Technical Verdict
The FLHR/07 remains a highly sought-after model on the secondary market because it bridges the gap between classic aesthetics and modern drivetrain efficiency. While it lacks the later 2009 frame redesign, the introduction of the 6-speed transmission makes it the first truly modern-era Road King suitable for sustained interstate speeds.
Frequently Asked Questions
Q: What is the recommended spark plug gap?
A: For the 6R12 plugs, the gap should be set between 0.038 and 0.043 inches (0.97 – 1.09 mm).
Q: Can I use 10W-40 oil?
A: Only in emergency situations or extremely cold climates. The air-cooled Twin Cam 96 generates significant heat; 20W-50 is the standard for engine protection.