| Specification | Value |
|---|---|
| Model Year | 2017 |
| Engine Architecture | Milwaukee-Eight 107 (Precision Cooled) |
| Engine Oil | SAE 20W50 H-D 360 (3.8 L) |
| Front Tire | 130/80B17 65H |
| Rear Tire | 180/65B16 81H |
| Tire Pressure (F/R) | 2.5 bar (36 psi) / 2.8 bar (40 psi) |
| Battery SKU | 66000175 |
| Spark Plugs | H-D 60100003 (4x) |
The 2017 model year marked a historic pivot for Harley-Davidson’s touring lineup. It was the inaugural year for the Milwaukee-Eight 107 engine, a power plant that introduced four-valve cylinder heads and a dual-spark ignition system to the Big Twin family. This engineering shift was largely driven by the stringent Euro 4 emissions standards, requiring more precise thermal management and combustion efficiency than the previous Twin Cam 103 could offer.
Engineering Highlight: The Dual Spark Transition
Unlike its predecessors, the FLHTK/L/17 utilizes a total of four spark plugs (H-D 60100003). This setup facilitates a faster flame front and more complete combustion, reducing hydrocarbon emissions while simultaneously increasing torque delivery. The “Twin Cooled” system on the Ultra Limited specifically targets the exhaust valves with liquid coolant, ensuring that the higher compression ratios necessitated by Euro 4 do not lead to thermal degradation under heavy touring loads.
Maintenance & Technical Guidelines
As the Editor-in-Chief of MotoSpecsLab, I emphasize that the Milwaukee-Eight platform requires strict adherence to its lubrication and electrical specifications to maintain peak performance.
Lubrication System
The 2017 Ultra Limited utilizes a dry-sump system. The recommended lubricant is SAE 20W50 Harley-Davidson 360. A full oil change including filter requires 3.8 liters. Given the increased heat profiles of Euro 4 compliant engines, synthetic lubricants (Screamin’ Eagle SYN3) are often preferred for high-ambient temperature touring.
Chassis and Contact Patch
The FLHTK and the Low (FLHTKL) variant utilize a specific bias-belted tire configuration to handle the 400kg+ wet weight.
- Front: 130/80B17 65H (Recommended 36 psi)
- Rear: 180/65B16 81H (Recommended 40 psi)
Maintaining these pressures is critical for the function of the Reflex Linked Brembo ABS system, which relies on consistent rolling diameters for accurate slip-rate calculations.
Electrical System
The 2017 models moved to a high-output charging system to support the Boom!™ Box Infotainment. The primary battery (66000175) must be maintained via a tender during storage, as the security system and ECU maintain a constant parasitic draw to monitor Euro 4 diagnostic sensors.
MotoSpecsLab Verdict
The 2017 FLHTK/L represents the bridge between traditional air-cooled aesthetics and modern emissions-compliant engineering. It is a robust platform, provided the owner respects the four-plug ignition service intervals and the precision-cooling fluid levels.
Frequently Asked Questions (FAQ)
A: The Milwaukee-Eight engine uses two plugs per cylinder to ensure faster combustion, which is necessary to meet Euro 4 emission standards while increasing power.
A: It is not recommended. The V-Twin architecture of the 107 engine is designed for the viscosity of 20W50 to protect against high-temperature shear.