Data as of: DVSA MOT results to 2025
Jawa 350/640 vs Kawasaki ZXR400
The Jawa 350/640 passes its MOT first time more often than the Kawasaki ZXR400: 88.0% vs 73.1%, a 14.9-point lead.
MOT reliability, side by side
| Metric | Jawa 350/640 | Kawasaki ZXR400 |
|---|---|---|
| First-time pass rate | 88.0% | 73.1% |
| Outright fail rate | 5.4% | 18.9% |
| Vs comparable bikes (age & mileage adjusted) | +1.6 pts | -9.9 pts |
| Engine size | 344cc | 398cc |
| Rank among all models | #1604 of 5428 | #4490 of 5428 |
| Median miles at test | 8,638 | 23,651 |
| MOT tests analysed | 518 | 14,200 |
| Most common failure | lighting and signalling | lighting and signalling |
First-time outcomes on normal tests, 2005–2025. "Most common failure" is the component group with the most recorded defects on failed tests. Read pass rates against test counts: a smaller sample is noisier. Source: DVSA anonymised MOT results.
"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.
What fails, side by side
| Component | Jawa 350/640 | Kawasaki ZXR400 |
|---|---|---|
| Lights & signalling | 3.1% | 9.1% |
| Steering & suspension | 1.5% | 7.9% |
| Brakes | 1.2% | 7.9% |
| Tyres & wheels | 1.5% | 4.0% |
| Fuel & exhaust | 1.2% | 2.4% |
| Structure & body | 1.0% | 2.2% |
| Drive system | 0.6% | 1.9% |
A test that fails on two components counts once in each. Component links go to the bikes most likely to fail on it.
Pass rate by test year
| Test year | Jawa 350/640 | Kawasaki ZXR400 |
|---|---|---|
| 2013 | 71.0% | 68.6% |
| 2021 | 97.3% | 81.2% |
| 2022 | 86.8% | 86.3% |
| 2023 | 91.4% | 82.8% |
| 2024 | 86.7% | 80.0% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Jawa 350/640 | Kawasaki ZXR400 |
|---|---|---|
| 0k-10k miles | 89.8% | 87.1% |
| 10k-20k miles | 90.2% | 77.4% |
| 20k-30k miles | 78.0% | 69.9% |
Bands with fewer than 30 tests for either bike are left out.
Jawa 350/640 vs Kawasaki ZXR400 FAQ
Which is more reliable, the Jawa 350/640 or the Kawasaki ZXR400?
The Jawa 350/640 passes its MOT first time more often than the Kawasaki ZXR400: 88.0% vs 73.1%, a 14.9-point lead. Adjusted for age, mileage and test class, the Jawa 350/640 still comes out ahead: +1.6 points vs comparable bikes for the Jawa 350/640, -9.9 for the Kawasaki ZXR400. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Jawa 350/640 fail its MOT on most?
Lights & signalling: 3.1% of Jawa 350/640 MOT tests failed on it, then steering & suspension (1.5%).
What does the Kawasaki ZXR400 fail its MOT on most?
Lights & signalling: 9.1% of Kawasaki ZXR400 MOT tests failed on it, then steering & suspension (7.9%).
Which holds up better at high mileage, the Jawa 350/640 or the Kawasaki ZXR400?
At 20k-30k miles the Jawa 350/640 passes first time more often: 78.0% for the Jawa 350/640 vs 69.9% for the Kawasaki ZXR400.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.