KAWASAKI Z550-G4
Pass rate over time
The Z550-G4's first-time pass rate has fallen 6.7 points since 2006, 78.1% to 71.4%.
Pass rate by mileage
A low-mileage Z550-G4 passes first time 89.1% of the time; by 50k that's 80.4%.
First-time pass rate by odometer reading at test, 10,000-mile bands for this model. Mileage is the strongest reliability signal. See the full curve.
What fails on a Z550-G4
| Component group | Share of defects | Defects | % of defects |
|---|---|---|---|
| brakes |
|
62 | 36.7 |
| lighting and signalling |
|
39 | 23.1 |
| steering and suspension |
|
32 | 18.9 |
| tyres and wheels |
|
12 | 7.1 |
| body and structure |
|
9 | 5.3 |
| reg plates and vin |
|
5 | 3 |
| lamps and reflectors |
|
4 | 2.4 |
| fuel and exhaust |
|
3 | 1.8 |
| driving controls |
|
2 | 1.2 |
| tyres |
|
1 | 0.6 |
Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.
How rivals compare
On first-time pass rate the Z550-G4 beats 1 of its 4 closest rivals (KAWASAKI ZX-6R, SUZUKI GSF600, YAMAHA FZS600).
Rivals share this bike's type and sit within ±30% of its engine capacity, ≥ 5,000 tests. Card colour = better/worse first-time pass rate than the Z550-G4.
Pass rate by registration year
Best year to buy used: 1990 (80.5% pass). Weakest: 1991 (68.2%).
First-time pass rate by the year each bike was first registered (cohorts with ≥ 50 tests). Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years.