Yamaha Unknown (1986)
1986 Yamaha Unknown
CarHunch analysed 18,025 real MOT records for the 1986 Yamaha Unknown. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.
This 1986 Yamaha has a 1.2% first-time pass rate—catastrophically below the UK average of 80%—meaning nearly every vehicle tested fails its MOT on first attempt. The dangerous defect rate of 0.1% is mercifully low, but the near-total failure rate is the real story here.
The median mileage of 15,693 miles is unusually low for a 38-year-old vehicle, suggesting most of these are either low-use classics or have incomplete mileage records; combined with zero average failures and advisories recorded, the data likely reflects incomplete MOT history for older, rarely-tested machines rather than genuine reliability. If you're considering one of these bikes, treat the MOT data as unreliable—focus instead on the machine's condition, service history, and whether it's been properly maintained through decades of storage.
What to check before buying a 1986 Yamaha Unknown
Practical pre-purchase checks for this age and model.
- 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
- 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
- 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
- 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.
Before you buy a Yamaha Unknown
MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.
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Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Petrol (100%) | 18,010 | 1.1% | 0 |
| Other (0%) | 10 | 93.3% | 0.2 |
| Diesel (0%) | 4 | 0% | 0 |
| Electric (0%) | 1 | 0% | 0 |
Mileage Distribution
Most 1986 Yamaha Unknown vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 1986 Yamaha Unknown vehicles fall between 6,004 and 25,901 miles.
1986 Yamaha Unknown — Still on the Road
Strong survival — 71 vehicles still getting MOTs in 2025, 100% of the peak.
Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2016–2025.
MOT History Averages
Most Common MOT Issues — 1986 Yamaha Unknown
Based on actual MOT test records for this model. Percentage shows how often each item appears across all vehicles in this cohort.
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8.7%
Exhaust noisy
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6.2%
Front Brake indicates slight fluctuation of brake effort
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6.2%
Rear Tyre worn close to the legal limit
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6%
Front Brake binding but not excessively
-
5.8%
Steering headbearing has slight free play
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5.5%
Rear Wheel bearing has slight play
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5.5%
Front Tyre worn close to the legal limit
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5.3%
Rear reflector missing
Data covers a 3-year window centred on 1986. Counts include advisories and failures.
Found a specific Yamaha Unknown?
Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.