Bsa D14/4 MOT Pass Rate
Overall pass rate across all manufacture years, based on 165 real MOT test results. Failure rate: 13.9%.
Data from official DVSA MOT testing records
Bsa D14/4 MOT Reliability Overview
The Bsa D14/4 is a rare vehicle in the UK, with 165 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 86.1% and a failure rate of 13.9%, which is well above the UK average of approximately 37%.
Based on this data, the Bsa D14/4 earns a "Excellent" reliability rating. The average Bsa D14/4 presents for MOT with approximately 16,090 miles on the clock. Manufacture year matters: 1968 models achieve the highest pass rate at 88.5%, while 1969 models have the lowest at 74.3%. This 14.2 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Bsa D14/4 is Motorcycle lighting and signalling, affecting 8.5% of all tests. Motorcycle lighting and signalling issues are a common cause of MOT failure. Regular inspection and maintenance of these components helps ensure your vehicle passes its MOT. The second most common issue is Motorcycle brakes at 3.6%. Motorcycle steering and suspension rounds out the top three at 3.6%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.
Top failures across all manufacture years combined. Individual year pages may show different top failures.
What Fails Most
Pass Rate by Manufacture Year
* High Fail Rate badge indicates an MOT pass rate below 65% (failure rate above 35%).
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Motorcycle Lighting And Signalling | 8.5% | 14 |
| 2 | Motorcycle Drive System | 6.1% | 10 |
| 3 | Motorcycle Brakes | 4.8% | 8 |
| 4 | Motorcycle Steering And Suspension | 3.6% | 6 |
| 5 | Motorcycle Tyres And Wheels | 3.0% | 5 |
| 6 | Items Not Tested | 0.6% | 1 |
| 7 | Motorcycle Body And Structure | 0.6% | 1 |
Failures per 10,000 Miles
avg. 16,090 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 lighting and signalling | 5.27 | 8.5% | 14 |
| Motorcycle drive system | 3.77 | 6.1% | 10 |
| Motorcycle brakes | 3.01 | 4.8% | 8 |
| Motorcycle steering and suspension | 2.26 | 3.6% | 6 |
| Motorcycle tyres and wheels | 1.88 | 3.0% | 5 |
| Items Not Tested | 0.38 | 0.6% | 1 |
| Motorcycle body and structure | 0.38 | 0.6% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Bsa D14/4 has 16,090 miles when tested for MOT.
📊 Mileage-Adjusted Failure Rate
How often this car fails MOT relative to how much it's driven — a fairer comparison than raw pass rate.
The Bsa D14/4 has a mileage-adjusted failure rate of 8.64% per 10,000 miles driven. The average across all makes is 5.38%, so this model is worse than average.
About Bsa D14/4 MOT Data
The Bsa D14/4 is a rare vehicle in the UK, with 165 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 86.1% and a failure rate of 13.9%, which is well above the UK average of approximately 37%.
For Bsa D14/4 owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on motorcycle lighting and signalling and motorcycle brakes for the best chance of a first-time pass. Use our detailed year-by-year breakdown and failure analysis below to understand how your specific D14/4 is likely to perform.
Motorcycle lighting and signalling — 8.5% of failures
Motorcycle lighting and signalling issues account for 8.5% of MOT failures on the Bsa D14/4. Motorcycle lighting and signalling 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.
Motorcycle brakes — 3.6% of failures
Motorcycle brakes issues account for 3.6% of MOT failures on the Bsa D14/4. 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 steering and suspension — 3.6% of failures
Motorcycle steering and suspension issues account for 3.6% of MOT failures on the Bsa D14/4. Suspension failures typically involve worn bushes, leaking shock absorbers, broken coil springs, and damaged suspension arms. These affect ride quality, tyre wear, and road holding. Typical repair costs: £200–500. Pre-MOT check: Look for uneven tyre wear, listen for clunking over bumps, and check if the car pulls to one side. A bouncy ride suggests worn shock absorbers. Visually inspect coil springs for cracks.
Frequently Asked Questions
What is the MOT pass rate for the Bsa D14/4?
Based on 165 MOT tests in our database, the Bsa D14/4 has an overall pass rate of 86.1% (13.9% fail rate).
What are the most common MOT failures on a Bsa D14/4?
The top 3 reasons a Bsa D14/4 fails its MOT are: 1. Motorcycle lighting and signalling (8.5%), 2. Motorcycle brakes (3.6%), 3. Motorcycle steering and suspension (3.6%). Check these areas before booking your MOT.
Is the Bsa D14/4 reliable?
With a 13.9% MOT failure rate, the D14/4 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Bsa D14/4?
Based on failure data, focus on: Motorcycle lighting and signalling (8.5%); Motorcycle brakes (3.6%); Motorcycle steering and suspension (3.6%). These are the areas most likely to cause a fail. Also check all lights, tyres (minimum 1.6mm tread), and windscreen condition — these are quick wins that apply to all cars.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.