Yamaha XT 660 X MOT pass rate and common failures
Yamaha XT 660 X motorcycles pass the MOT 83.45% of the time, measured across 284 tests in the DVSA record. A further 6.69% 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 46.4% of failed tests on this model.
- Then check does not conform to the specified requirements and has a serious fluid leak, the next two most common reasons.
- Age matters here: 91.11% of 11-15 year old examples pass, against 79.9% at 16+ years - a gap of 11.2 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 (13.4% of all tests) - not a failure, but money you will spend sooner or later.
- Average recorded mileage at test is 19,979 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 | 91.11% | 90 | |
| 16+ years | 79.9% | 194 |
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 | 46.4% | 13 | |
| 2 | Does not conform to the specified requirements | 25% | 7 | |
| 3 | Has a serious fluid leak | 17.9% | 5 | |
| 4 | Missing | 17.9% | 5 | |
| 5 | Tread depth is below minimum requirements of 1.0mm | 17.9% | 5 | |
| 6 | Flashing more than 120 times a minute | 14.3% | 4 | |
| 7 | Insecure | 14.3% | 4 | |
| 8 | Less than 1.0 mm thick | 14.3% | 4 | |
| 9 | Obviously incorrectly positioned | 14.3% | 4 | |
| 10 | Not working on main beam | 10.7% | 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 | 13.4% | 38 | |
| 2 | Tread depth is below minimum requirements of 1.0mm | 4.9% | 14 | |
| 3 | Significantly and obviously worn | 4.2% | 12 | |
| 4 | Has a serious fluid leak | 3.5% | 10 | |
| 5 | Less than 1.0 mm thick | 3.5% | 10 | |
| 6 | Has excessive play | 2.5% | 7 | |
| 7 | In such a condition that it is seriously weakened | 2.5% | 7 | |
| 8 | Worn to excess | 2.5% | 7 | |
| 9 | Has a major leak of exhaust gases | 2.1% | 6 | |
| 10 | Indicates excessive fluctuation of brake effort | 2.1% | 6 |
Yamaha XT 660 X for sale
No Yamaha XT 660 X in stock at the moment - 83 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 | |
| Suzuki GSF600 · 600cc | 4,890 | 80% | 29,308 | |
| Honda CBR600F · 599cc | 4,710 | 85.56% | 30,651 | |
| Kawasaki ZX-6R · 599-636cc | 4,510 | 81.62% | 26,019 | |
| Suzuki SV650 · 646cc | 3,834 | 80.99% | 27,644 |
Source: DVSA MOT testing data, 2025 · updated Aug 2026 · licence and method