| Parameter | Specification |
|---|---|
| Production Years | 2018–2020 |
| Engine Type | Milwaukee-Eight 107 CUI |
| Engine Oil | SAE 20W-50 HD 360 (4.3 L) |
| Front Tire | 130/60B21 63H (36 psi) |
| Rear Tire | 240/40R18 79V (42 psi) |
| Spark Plugs | HD 60100003 |
| Battery Part No. | 66000207 |
Engineering Insight: The 2018 launch of the FXBR Breakout marked a radical departure for Harley-Davidson’s Softail line. It was the first time the company integrated the dual-counterbalanced Milwaukee-Eight engine into a chassis that was 34% stiffer and significantly lighter than previous generations. This engineering shift allowed the Breakout to maintain its signature low-slung dragster silhouette while finally offering the lean angles and structural rigidity required for modern performance riding.
Technical Deep-Dive: The Milwaukee-Eight 107
At the heart of the FXBR is the 107 cubic-inch Milwaukee-Eight powertrain. Unlike the older Twin Cam engines, the M8 features a single camshaft design which reduces mechanical noise and allows for a narrower primary drive. The dual-spark plug configuration per cylinder ensures more efficient combustion, essential for meeting Euro 4 and 5 emissions while providing the immediate torque delivery Breakout owners expect.
Maintenance Guide & Fluid Dynamics
For optimal longevity, MotoSpecsLab recommends adhering strictly to the 4.3L oil capacity using SAE 20W-50. Overfilling can lead to carry-over issues into the air cleaner, a common oversight in high-torque V-twins. The 21-inch front wheel and massive 240mm rear tire require precise pressure management (36 psi front / 42 psi rear) to prevent irregular cupping and to ensure the bike tips into corners predictably despite the wide rear contact patch.
Electrical System & Ignition
The FXBR utilizes a high-output charging system designed to support the signature Daymaker LED headlamp. When replacing the battery, the 66000207 AGM unit is specified for its vibration resistance—critical given the rigid-mount nature of the engine within the Softail frame. For ignition maintenance, the HD 60100003 plugs should be gapped according to factory service manuals to prevent high-load misfires.
Performance Verdict
The Breakout 107 is a masterclass in aesthetic-driven engineering. While its geometry favors straight-line stability, the weight reduction achieved in the 2018 redesign makes it surprisingly flickable compared to its predecessor. It remains a top choice for riders seeking a “factory custom” look with the reliability of modern Milwaukee-Eight architecture.