Engine “redline” intervention is elevated from 5600 rpm (Milwaukee-Eight 117 Classic and Custom engines) to 5900 rpm to give additional throttle headroom under strong acceleration.
Review – Key Features – Features & Benefits – Specifications
2025 Harley-Davidson Milwaukee-Eight 117 H.O. Engine: AGRESSIVE UPPER RPM.
Introducing the 2025 Harley-Davidson Milwaukee-Eight 117 H.O. Engine…
Milwaukee-Eight 117 H.O. (powers Low Rider S and Low Rider ST models) is tuned for riders that consistently seek performance in the upper RPM range and desire an aggressive sound profile. This engine delivers 114 horsepower (85 kW) and 128 lb. ft. peak torque (174 Nm) for an exciting boost in performance – 11 percent more peak horsepower (114 vs 103 horsepower) – compared to the 2024 Milwaukee-Eight 117 in the Low Rider S and Low Rider ST models. The high-performance SE8-511 camshaft developed for the Milwaukee-Eight 121 High Output engine in the CVO™ Road Glide ST model delivers a top-end performance boost for strong acceleration in the mid and upper RPM range. Engine “redline” intervention is elevated from 5600 rpm (Milwaukee-Eight 117 Classic and Custom engines) to 5900 rpm to give additional throttle headroom under strong acceleration. The Heavy Breather intake features an exposed forward-facing air filter element to maximize flow and adds intake tuning length that improves charging efficiency and peak torque. This intake also gives this engine high-performance style and spirited intake sound on acceleration. A 2-into-1 exhaust enhances engine performance by promoting efficient scavenging of exhaust from the engine cylinders while it delivers a satisfying low rumble at idle and powerful exhaust note under acceleration.
More Power Potential – Each of the new Milwaukee-Eight 117 powertrain variants for Cruiser models offer significantly more performance potential with the installation of Screamin’ Eagle Stage Kits and Screamin’ Eagle intake and exhaust components, compared to 2024 Milwaukee-Eight 114/117 engines.
2025 Harley-Davidson Milwaukee-Eight 117 H.O. Engine Totalmotorcycle.com Key Features
Three New Milwaukee-Eight 117 Powertrains – The 2025 Cruiser models will be powered by one of three new Milwaukee-Eight 117 powertrain variants with new cylinder heads, throttle body and intake manifold. Each is tuned – through difference in intake and exhaust scheme and ride mode programming – to offer performance that matches the personality of a specific Cruiser model and the anticipated expectations of that model’s customer. Each engine is Euro V+ Compliant (2024 emissions standards). Shared features of these engines include:
- NEW Four-Valve Cylinder Heads feature the combustion chamber shape, oval intake ports and low-profile intake valve seats as introduced on 2023/24 Milwaukee-Eight 117/121 engines for Grand American Touring and CVO models. These heads are designed to improve performance and fuel economy.
- NEW Engine Oil is routed from a frame-mounted oil cooler through cylinder head cooling passages. This cylinder head cooling system further optimizes thermal comfort for the rider, especially in low-speed riding situations and hot weather. This air/oil cooled version of the Milwaukee-Eight 117 engine weighs less that the Grand American Touring/CVO versions of the engine and does not require coolant system maintenance.
- NEW Contoured Aluminum Intake Manifold offers a more-direct air path and creates a smooth transition from the round throttle body to the new oval intake ports to enhance intake air flow for improved power and reduced exhaust emissions.
- NEW Improved Sound Quality as muffler and intake have been designed to enhance sound quality and match the character of each engine variant. Mufflers feature advanced lightweight material that works to trim high frequencies and emphasize low frequencies for a powerful sound.
- Dual Counter-Balancers are tuned to eliminate primary vibration at idle while permitting some engine character to shine through at speed.
- V-Twin Design with 45-degree cylinder angle maintains classic Harley-Davidson look-sound-feel.
- Compression Ratio of 10.3:1 enhances torque at lower RPM and improves fuel economy.
2025 Harley-Davidson Milwaukee-Eight 117 H.O. Engine Totalmotorcycle.com Features and Benefits
- NEW Milwaukee-Eight 117
- A Milwaukee-Eight 117 powertrain with more displacement and enhanced intake and exhaust flow offers 105 horsepower (78 kW) and 130 lb. ft (176 Nm) of peak torque, 6.6 percent more torque and 12.9 percent more horsepower than the Twin Cooled Milwaukee-Eight 114 powertrain in 2024 Grand American Touring models.
- Milwaukee-Eight 117-cylinder head cooling system further optimizes engine temperatures, especially in low-speed riding situations and hot weather, compared to 2024 Twin-Cooled Milwaukee-Eight 114 engine.
2025 Harley-Davidson Milwaukee-Eight 117 H.O. Engine – Totalmotorcycle.com Specifications/Technical Details
| Engine | Milwaukee-Eight® 117 High-Output | |
| Valves | Pushrod-operated, overhead valves with hydraulic, self-adjusting lifters; four valves per cylinder | |
| Bore | 4.075 in. (103.5 mm) | |
| Stroke | 4.5 in. (114.3 mm) | |
| Displacement | 117 cu in (1,923 cc) | |
| Compression Ratio | 10.3:1 | |
| Fuel System | Electronic Sequential Port Fuel Injection (ESPFI) | 3 |
| Air Cleaner | NEW Heavy Breather intake with synthetic media, washable exposed element | |
| Exhaust | 2-into-1; catalyst in header | |
| Lubrication System | Pressurized, dry-sump with oil cooler |
Manufacturer Specifications and appearance are subject to change without prior notice on Total Motorcycle (TMW).
