Cruisers
1991Harley-Davidson Fat Boy
31 fields on record
The 1991 Harley-Davidson Fat Boy is an iconic cruiser built for riders seeking classic styling and commanding presence. Known for its distinctive solid disc wheels, low-slung stance, and Evolution V-twin engine, the Fat Boy delivers authentic cruiser character with accessible power. Its 1337cc air-cooled engine and substantial 298kg weight make it ideal for leisurely highway riding and commanding attention.
- Capacity
- 1337.0 ccm
- Engine
- V-Twin, four-stroke
- Gearbox
- 5-speed
- Dry weight
- 295.0 kg
- Seat height
- 673 mm
- Power
- 49.0 HP (36.0 kW) @ 5000 RPM
What’s new for the 1991 Harley-Davidson Fat Boy
vs the 1990| Spec | 1990 | 1991 |
|---|---|---|
| Power | 49.0 HP (36.0 kW) | 49.0 HP (36.0 kW) @ 5000 RPM |
Other years
1990
1991
1992
1993
1994
1995
1996
1997
2013
2014
2015
2016
2017
2018
2019
2020
2025
2026
How it rides
Editorial estimate from the spec sheet - not lab tested- Best for
- Built for boulevard cruising and making a bold visual statement rather than outright performance or long-distance touring.
- Built for
- A muscular, iconic cruiser with a fat rear tire stance, strong low-end torque, and unmistakable classic Harley presence.
- Not ideal for
- Not the right choice for riders seeking nimble cornering, off-road capability, or a lightweight, agile everyday commuter.
Scores are derived from the spec sheet using the same model across every bike, so they compare like for like.
Will it fit you?
Worked out in your browser - nothing is sent to usReliability & safety
Bike Reliability score, safety recalls and owner complaintsBike Reliability
How the score works →84
out of 100Excellent
The 1991 Harley-Davidson Fat Boy passed its annual roadworthiness test first time 90.5% of the time, 7.3 points above expected for bikes of the same age and mileage. That beats 84% of models.
All years of this model: 83 / 100 (excellent) from 6,083 tests.
90.5%Passed first time
5.3%Failed outright
4.1%Fixed during test
15,000Typical miles
169Tests
Pass rate against other bikes
Share of first tests passed with nothing failed or fixed during the test. Same age is what bikes of the same age and mileage pass on average; all bikes is the average over every bike tested, 2005–2025. The score compares this bike with the same-age figure.
Pass rate by miles ridden
All years of this model.
Score by year first registered
66
84
83
70
91
90
74
77
78
84
85
85
81
88
87
'90'91'92'93'94'95'96'97'98'12'13'14'17'18'19
What it fails on
Share of its failed tests that had a fault in each area (one test can fail on several), against all bikes.
From 365 failed tests, 2018–2025. In brackets and marked on each bar: all bikes.
Against its rivals · ranks 1 of 6
| # | Model (all years) | Score | Tests |
|---|---|---|---|
| 1 | Harley-Davidson Fat Boy | 83 Excellent | 6,083 |
| 2 | Harley-Davidson Springer Softail | 74 Good | 398 |
| 3 | Yamaha XV 1100 Virago | 62 Good | 11,113 |
| 4 | Harley-Davidson FXR 1340 Super Glide | 61 Good | 216 |
| 5 | Suzuki VS 1400 Intruder | 45 Average | 1,109 |
| 6 | Harley-Davidson XLH Sportster 1200 | 36 Below average | 718 |
Rivals are the most-viewed bikes on MotorcycleDB in the same category and engine size, from within three years of this model.
From British annual roadworthiness tests, 2005-2025. Contains public sector information licensed under the Open Government Licence v3.0 (DVSA MOT test data, Great Britain). How Bike Reliability works.
Engine
- Capacity
- 1337.0 ccm
- Power
- 49.0 HP (36.0 kW) @ 5000 RPM
- Engine type
- V-Twin, four-stroke
- Power/weight ratio
- 0.1661 HP/kg (dry)
- Bore x stroke
- 88.8 x 108.0 mm
- Compression
- 8.5:1
- Cooling system
- Air
- Fuel system
- Carburettor
- Starting
- Electric
- Valves per cylinder
- 2
- Torque
- Not on record - add it
Transmission
- Gearbox
- 5-speed
- Transmission type
- Manual
- Final drive
- Belt
Performance
- Top speed
- 148.0 km/h (92.0 mph)
Dimensions & weight
- Wheelbase
- 1651 mm
- Overall length
- 2365 mm
- Overall width
- 1016 mm
- Seat height
- 673 mm
- Dry weight
- 295.0 kg
- Wet weight
- 298.0 kg
- Fuel capacity
- 16.00 litres
- Ground clearance
- 125 mm
Chassis & suspension
- Front suspension
- Dual-bending valve 49 mm telescopic with aluminum fork triple clamps; dual rate spring; "beer can" covers
- Rear suspension
- Hidden, free piston, coil-over monoshock; 43mm stroke; hydraulic preload adjustment
- Rake (fork angle)
- 30.0°
- Trail
- 104 mm
Brakes & wheels
- Front brakes
- Single disc
- Rear brakes
- Single disc
- Front tyre
- MT 90-16
- Rear tyre
- MT 90-16
Specs last verified against published sources: .
Compiled from manufacturer documentation and user contributions, corrected on an ongoing basis. Spotted something wrong? Tell us.
What changed, year to year
Differences highlighted| Specification | 1990 | 1991 | 1994 | 2014 | 2018 | 2026 |
|---|---|---|---|---|---|---|
| Capacity | 1337 cc | 1337 cc | 1337 cc | 1690 cc | 1746 cc | 1923 cc |
| Dry weight | 295 kg | 295 kg | 295 kg | 284 kg | 284 kg | 284 kg |
| Seat height | 673 mm | 673 mm | 673 mm | 654 mm | 654 mm | 658 mm |
| Fuel capacity | 16 L | 16 L | 16 L | — | — | 18.9 L |
| Bike Reliability ⓘ | 66 Good | 84 Excellent | 91 Excellent | 85 Excellent | 88 Excellent | Too new |
Illustrative - generated automatically by diffing the year records already on file, not a manufacturer-published changelog.
Rider Reviews
Common questions
Is the Harley-Davidson Fat Boy reliable?
The 1991 Harley-Davidson Fat Boy has a Bike Reliability score of 84 out of 100 (excellent), better than 84% of models. It passed its annual roadworthiness test first time 90.5% of the time against 82.0% for all bikes, 7.3 points above what is expected for bikes of the same age and mileage. Across all years, its most common reason to fail is lights & indicators (59% of failed tests). Based on 169 tests in Great Britain.
What is the engine size of the Harley-Davidson Fat Boy?
The 1991 Harley-Davidson Fat Boy has a Capacity of 1337.0 ccm (81.59 cubic inches).
What engine power does the Harley-Davidson Fat Boy have?
The 1991 Harley-Davidson Fat Boy has a Power of 49.0 HP (36.0 kW) @ 5000 RPM.
How many gears does the Harley-Davidson Fat Boy have?
The 1991 Harley-Davidson Fat Boy has a Gearbox of 5-speed.
How much does the Harley-Davidson Fat Boy weigh?
The 1991 Harley-Davidson Fat Boy has a Dry weight of 295.0 kg (650.4 pounds).
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Similar bikes
Same category, weighted similarity
1991 Harley-Davidson FXSTC 1340 Softail Custom
1331 cc · 298 kg
1991 Harley-Davidson FXST 1340 Softail
1337 cc · 290 kg
1996 Suzuki VS 1400 GLP Intruder
1360 cc · 244 kg · 735 mm
1995 Suzuki VS 1400 Intruder
1360 cc · 243 kg · 725 mm
1991 Kawasaki VN-15 SE
1470 cc · 281 kg
1992 Kawasaki VN-15 SE
1470 cc · 281 kg
The 1991 Harley-Davidson Fat Boy is an iconic and timeless motorcycle model that has become a symbol of the Harley-Davidson brand. With its distinctive design, powerful engine, and smooth ride, the Fat Boy has remained a top choice for motorcycle enthusiasts for over two decades. Whether you're cruising down the highway or taking on winding country roads, the Fat Boy delivers a thrilling and exhilarating riding experience. Its classic styling and high-performance capabilities make it a standout choice for riders who value both form and function in their motorcycle.
The 1991 Harley-Davidson Fat Boy offers a perfect blend of traditional design and modern engineering, making it a standout choice for riders of all levels. Its 1340cc V-twin engine provides plenty of power and torque, while its comfortable seating and smooth handling make it an ideal choice for long rides. With its iconic looks and exceptional performance, the 1991 Fat Boy continues to be a popular choice for motorcycle enthusiasts looking for a timeless and reliable ride.
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