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2025 Harley-Davidson Softail Fat Boy 117 Overview
For 2025, Harley-Davidson offers the Softail Fat Boy 117 as a custom / cruiser motorcycle with 1923 cc on tap. The 2025 Harley-Davidson Softail Fat Boy 117 is built around a Four stroke, V-Twin, 2 Milwaukee-Eight 117 custom, Pushrod-operated, overhead valves with hydraulic, self-adjusting lifters, 4 valves per cylinder engine, a compression ratio of 10.3:1. Out on the road, the Softail Fat Boy 117 delivers 77 kW @ 4800 rpm of peak power and 171 Nm @ 3000 rpm of torque. In everyday use, the 2025 Softail Fat Boy 117 tips the scales at 315 kg, carries a 18.9-litre fuel tank, offers a seat height of Unladen 675 mm and spans a 1650 mm wheelbase. That's roughly 14.4 kg heavier than the average custom / cruiser motorcycle in our database. Every technical detail, from suspension travel to tyre sizes, is covered in the full 2025 Harley-Davidson Softail Fat Boy 117 spec sheet below.
2025 Softail Fat Boy 117 - Pros & Cons
Strengths
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Strong power output: Peak output on the Softail Fat Boy 117 is 77 kW @ 4800 rpm and 171 Nm @ 3000 rpm of torque - strong numbers for what it is.
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Fuel injection: No choke, no jetting, no altitude compensation to think about - fuel injection just works across a wider range of conditions than carburetion.
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Accessible seat height: At just Unladen 675 mm, flat-footing at a stop is easy for most riders - a genuine confidence builder for less experienced owners.
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Large fuel range: With a 18.9-litre tank, this isn't a bike you'll be stopping for fuel every hour - a real asset on longer trips.
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Low-maintenance final drive: Belt, 32/66 ratio final drive is about as close to maintenance-free as motorcycle drivetrains get.
Considerations
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Age-related wear: No particular mechanical concern flags for the Softail Fat Boy 117 - condition on any used example comes down to how well it's been looked after.
Wear Points & Servicing Notes
Heat management in traffic
Air cooling on the Softail Fat Boy 117 keeps the mechanical layout simple, but heat management in slow traffic needs more attention than on a liquid-cooled bike - plan routes and gear accordingly in warmer conditions.
Fuelling & injector care
Fuelling on the Softail Fat Boy 117 comes from Electronic Sequential Port Fuel Injection (ESPFI). Cold starts and throttle response stay consistent across altitude and temperature, the main practical edge over a carbureted equivalent.
Brake disc and pad wear
2 x 300mm discs, 4 piston fixed caliper up front provides the primary stopping power; inspect disc thickness and pad wear at each tyre change to catch scoring before it becomes a rotor replacement.
Suspension condition on used examples
Suspension duties are handled by Dual bending valve 49mm telescopic with aluminum fork triple clamps, dual rate spring, "beer can" covers up front and Hidden, free piston, coil-over monoshock, 43mm stroke, hydraulic preload adjustment at the rear. Weeping fork seals aren't a dealbreaker on a used bike, but they're a fair basis for negotiating price.
Final drive maintenance
Belt final drive keeps day-to-day maintenance minimal on the Softail Fat Boy 117 - just periodic tension and wear checks rather than the regular cleaning a chain demands.
Frame & chassis check
The Mild steel, tubular frame, rectangular section backbone, stamped, cast, and forged junctions, MIG welded, aluminum forged fender supports chassis holds up well with normal use; on a used bike it's still worth checking the head-stock and swingarm pivot area for impact damage or corrosion.
Handling the weight at a standstill
The Softail Fat Boy 117's 315 kg kerb weight is worth factoring into how you handle it at a standstill - parking-lot manoeuvres need a bit more deliberate technique than on a lighter machine.
Softail Fat Boy 117 - Buying & Maintenance Guide
What to check before buying
A pre-purchase check on the 2025 Harley-Davidson Softail Fat Boy 117 should cover the same ground every time: service history, chain and sprocket condition, and any oil seepage around the casings. Start it from cold if you can - a well-kept Softail Fat Boy 117 settles to a smooth idle within seconds.
Oil and filter changes
Oil changes are the cheapest insurance you can buy for a Softail Fat Boy 117's engine - keep to the manufacturer's interval rather than stretching it. Use the viscosity grade the manual specifies, not whatever's on sale.
Fuel system care
Injector systems like the Softail Fat Boy 117's hold up well with basic care - decent fuel, an occasional cleaner additive, and draining old fuel before any layup longer than three months.
2025 Harley-Davidson Softail Fat Boy 117 - Frequently Asked Questions
What engine does the 2025 Harley-Davidson Softail Fat Boy 117 have?
The 2025 Harley-Davidson Softail Fat Boy 117 uses a Four stroke, V-Twin, 2 Milwaukee-Eight 117 custom, Pushrod-operated, overhead valves with hydraulic, self-adjusting lifters, 4 valves per cylinder engine with 1923 cc of displacement. It is air cooled.
How much does the 2025 Harley-Davidson Softail Fat Boy 117 weigh?
The 2025 Harley-Davidson Softail Fat Boy 117 weighs 315 kg. This is the manufacturer's wet figure.
How much power does the 2025 Harley-Davidson Softail Fat Boy 117 make?
The 2025 Harley-Davidson Softail Fat Boy 117 produces 77 kW @ 4800 rpm of power and 171 Nm @ 3000 rpm of torque. These are peak figures.
What is the fuel tank capacity of the 2025 Harley-Davidson Softail Fat Boy 117?
The 2025 Harley-Davidson Softail Fat Boy 117 has a 18.9-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 315-377 km between stops.
Is the 2025 Harley-Davidson Softail Fat Boy 117 suitable for shorter riders?
The 2025 Harley-Davidson Softail Fat Boy 117 has a seat height of Unladen 675 mm. This is a comfortable, accessible height for most riders.
What brakes does the 2025 Harley-Davidson Softail Fat Boy 117 have?
The 2025 Harley-Davidson Softail Fat Boy 117 uses 2 x 300mm discs, 4 piston fixed caliper at the front and Single 292mm disc, 2 piston floating caliper at the rear.
What tyre sizes does the 2025 Harley-Davidson Softail Fat Boy 117 use?
The 2025 Harley-Davidson Softail Fat Boy 117 runs 160/60R18,70V,BW front and 240/40R18,79V,BW rear tyres. A good selection of sport, touring and all-weather rubber is available in these sizes.
What gearbox does the 2025 Harley-Davidson Softail Fat Boy 117 have?
The 2025 Harley-Davidson Softail Fat Boy 117 is fitted with a 6 Speed transmission.
Key Specifications
Engine
Four stroke, V-Twin, 2 Milwaukee-Eight 117 custom, Pushrod-operated, overhead valves with hydraulic, self-adjusting lifters, 4 valves per cylinder
Power
77 kW / 104Hp @ 4800 rpm
Torque
171 Nm / 126 lb-ft @ 3000 rpm
Top Speed
Not published by manufacturer
Fuel Capacity
18.9 Litres / US 5.0 gal
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Full 2025 Harley-Davidson Softail Fat Boy 117 Specifications
Year
2025
Make Model
Harley Davidson Softail Fat Boy 117
Seat Height
Unladen 675 mm / 26.6 in Laden 658 mm / 25.9 in
Wheelbase
1650 mm / 65 in
Ground Clearance
125 mm / 4.9 in
Height
1120 mm / 44.1 in
Length
2365 mm / 93.1 in
Width
965 mm / 40.0 in
Dry Weight
303 kg / 668 lbs
Fuel Capacity
18.9 Litres / US 5.0 gal
Wet Weight
315 kg / 694 lbs
Displacement
1923 cc / 117 cu in
Engine Detail
Four stroke, V-Twin, 2 Milwaukee-Eight 117 custom, Pushrod-operated, overhead valves with hydraulic, self-adjusting lifters, 4 valves per cylinder
Bore x Stroke
103.5 x 114.3 in
Compression Ratio
10.3:1
Cooling System
Air cooled
Exhaust
2-into-2 staggered, catalyst in muffler
Fuel Induction
Electronic Sequential Port Fuel Injection (ESPFI)
Ignition
Single-fire, non-wasted, map-controlled spark ignition
Lubrication
Pressurized, dry-sump with oil cooler
Starter
Electric
Clutch
Mechanical, 10 plate wet, assist & conventional
Final Drive
Belt, 32/66 ratio
Gear Ratios
1st 9.311 / 2nd 6.454 / 3rd 4.793 / 4th 3.882 / 5th 3.307 / 6th 2.79
Primary Drive
Chain, 34/46 ratio
Transmission / Drive
6 Speed
Frame Type
Mild steel, tubular frame, rectangular section backbone, stamped, cast, and forged junctions, MIG welded, aluminum forged fender supports
Suspension - Front
Dual bending valve 49mm telescopic with aluminum fork triple clamps, dual rate spring, "beer can" covers
Suspension - Rear
Hidden, free piston, coil-over monoshock, 43mm stroke, hydraulic preload adjustment
Lean Angle
25.6°
Rake
30°
Swingarm
Mild steel, tubular sections, stamped x-member, forged axle junctions, MIG welded, removable belt spacer
Trail
104 mm / 4.1 in
Wheel Travel - Front
130 mm / 5.1 in
Wheel Travel - Rear
86 mm / 3.4 in
Brakes - Front
2 x 300mm discs, 4 piston fixed caliper
Brakes - Rear
Single 292mm disc, 2 piston floating caliper
ABS
Standard
Tyres - Front
160/60R18,70V,BW
Tyres - Rear
240/40R18,79V,BW
Wheels
Machined, Lakester cast aluminum
Wheels - Front
18 x 4,5 in
Wheels - Rear
18 x 8.0 in
Specifications are compiled from manufacturer documentation and cross-referenced
technical sources, and corrected on an ongoing basis.
Spot an error? Let us know.
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