Yamaha XT 660 X MOT pass rate and common failures
Yamaha XT 660 X motorcycles pass the MOT 84.17% of the time, measured across 537 tests in the DVSA record. A further 7.08% passed only after a defect was put right at the test station.
What to check before the MOT
Built from this model's own failure record, not general advice.
- Start with not working - it accounts for 48.9% of failed tests on this model.
- Then check missing and tread depth is below minimum requirements of 1.0mm, the next two most common reasons.
- Age matters here: 87.92% of 11-15 year old examples pass, against 82.69% at 16+ years - a gap of 5.2 points.
- The most common advisory is noise is clearly in excess of that emitted by a similar motorcycle fitted with a standard silencer in average condition (14.3% of all tests) - not a failure, but money you will spend sooner or later.
- Average recorded mileage at test is 20,662 miles, which is the number to compare any advert against.
Pass rate by age
A single pass rate hides the most useful thing in this data: how the same model behaves at three years old and at fifteen.
| Age at test | Pass rate | Tests | |
|---|---|---|---|
| 11-15 years | 87.92% | 149 | |
| 16+ years | 82.69% | 387 |
Why the Yamaha XT 660 X fails
Share of failed tests on this model where the item was recorded. One test can fail on several items, so the column does not add up to 100%.
| # | Item | Of failures | Tests | |
|---|---|---|---|---|
| 1 | Not working | 48.9% | 23 | |
| 2 | Missing | 19.1% | 9 | |
| 3 | Tread depth is below minimum requirements of 1.0mm | 19.1% | 9 | |
| 4 | Does not conform to the specified requirements | 14.9% | 7 | |
| 5 | Insecure | 12.8% | 6 | |
| 6 | Has a serious fluid leak | 10.6% | 5 | |
| 7 | Flashing more than 120 times a minute | 8.5% | 4 | |
| 8 | Less than 1.0 mm thick | 8.5% | 4 | |
| 9 | Obviously incorrectly positioned | 8.5% | 4 | |
| 10 | Not working on main beam | 6.4% | 3 |
Most common advisories
Not a failure and not a legal requirement to fix - but an advisory that repeats year after year is money the next owner spends.
| # | Item | Of all tests | Tests | |
|---|---|---|---|---|
| 1 | Noise is clearly in excess of that emitted by a similar motorcycle fitted with a standard silencer in average condition | 14.3% | 77 | |
| 2 | Tread depth is below minimum requirements of 1.0mm | 5.6% | 30 | |
| 3 | Significantly and obviously worn | 3.9% | 21 | |
| 4 | Has a serious fluid leak | 3.5% | 19 | |
| 5 | Less than 1.0 mm thick | 3.2% | 17 | |
| 6 | Has excessive play | 2.6% | 14 | |
| 7 | Worn to excess | 2.4% | 13 | |
| 8 | Indicates excessive fluctuation of brake effort | 2.2% | 12 | |
| 9 | In such a condition that it is seriously weakened | 1.3% | 7 | |
| 10 | Has a major leak of exhaust gases | 1.1% | 6 |
Yamaha XT 660 X for sale
No Yamaha XT 660 X in stock at the moment - 87 other Yamaha bikes are advertised.
Similar bikes compared
Models of comparable capacity, so the comparison means something.
| Model | Tests | Pass rate | Avg mileage | |
|---|---|---|---|---|
| Honda CB 397-750cc · 397-750cc | 5,400 | 89.76% | 19,444 | |
| Honda NC · 741cc | 5,311 | 89.53% | 22,765 | |
| Honda CBR600F · 599cc | 4,914 | 85.61% | 30,486 | |
| Suzuki GSF600 · 600cc | 4,890 | 80% | 29,308 | |
| Kawasaki ZX-6R · 599-636cc | 4,713 | 81.54% | 26,085 | |
| Royal Enfield INTERCEPTOR INT 650 · 649cc | 4,016 | 91.24% | 5,914 |
Source: DVSA MOT testing data, 2025 · updated Aug 2026 · licence and method