1991 Harley Davidson Fat Boy MOT Pass Rate
Pass rate for Fat Boy models manufactured in 1991, based on 66 real MOT test results.
Data from official DVSA MOT testing records
1991 Harley Davidson Fat Boy MOT Analysis
The 1991 Harley Davidson Fat Boy has an MOT pass rate of 87.9% based on 66 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 18,960 miles on the odometer. With a 12.1% failure rate, the 1991 Fat Boy is rated as "Excellent" for MOT reliability.
The leading cause of MOT failure for the 1991 Harley Davidson Fat Boy is Motorcycle brakes, responsible for 1.5% of failures. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs range from £150–400. Motorcycle tyres is the second most common issue at 1.5%. Non-component advisories follows at 1.5%.
Top failures specific to 1991 models only. The overall Fat Boy page may show different rankings.
What Fails Most
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Motorcycle Brakes | 1.5% | 1 |
| 2 | Motorcycle Tyres | 1.5% | 1 |
| 3 | Non-component Advisories | 1.5% | 1 |
Failures per 10,000 Miles
avg. 18,960 miFor every 10,000 miles driven, this shows what percentage of MOT tests fail for each category. This accounts for how far cars are actually driven, not just raw pass/fail counts.
View as table
| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Motorcycle brakes | 0.80 | 1.5% | 1 |
| Motorcycle tyres | 0.80 | 1.5% | 1 |
| Non-component advisories | 0.80 | 1.5% | 1 |
Mileage Statistics
Mileage-adjusted failure rate — accounts for how much this model year is typically driven.
About This Data
The 1991 Harley Davidson Fat Boy has an MOT pass rate of 87.9% based on 66 tests — well above the UK average for UK vehicles. Cars of this vintage present for MOT with an average of 18,960 miles on the odometer. With a 12.1% failure rate, the 1991 Fat Boy is rated as "Excellent" for MOT reliability.
If you own or are considering buying a 1991 Harley Davidson Fat Boy, you can expect reliable MOT performance overall. Before your MOT, pay particular attention to motorcycle brakes: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm). With relatively low average mileage of 18,960 miles, many of these vehicles are still in good mechanical condition.
Motorcycle brakes — 1.5% of failures
Motorcycle brakes issues account for 1.5% of MOT failures on 1991 Harley Davidson Fat Boy models. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs: £150–400. Pre-MOT check: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm).
Motorcycle tyres — 1.5% of failures
Motorcycle tyres issues account for 1.5% of MOT failures on 1991 Harley Davidson Fat Boy models. Tyre failures include tread depth below the legal minimum of 1.6mm, cuts, bulges, exposed cords, and incorrect tyre pressure. Tyres are one of the most common and easiest-to-prevent MOT failures. Typical repair costs: £50–200 per tyre. Pre-MOT check: Check tread depth with a 20p coin — if the outer band is visible, the tyre is too worn. Look for bulges, cuts, or embedded objects. Ensure all tyres match the recommended size and load rating.
Non-component advisories — 1.5% of failures
Non-component advisories issues account for 1.5% of MOT failures on 1991 Harley Davidson Fat Boy models. Non-component advisories issues are a common cause of MOT failure. Regular inspection and maintenance of these components helps ensure your vehicle passes its MOT. Typical repair costs: £100–400. Pre-MOT check: Have this system checked during regular servicing. Look for warning signs like unusual noises, vibrations, or dashboard warning lights.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.