Data as of: DVSA MOT results to 2025
SUZUKI GN400
The pass rate is the MOT first-time pass: a roadworthiness check of the items an MOT covers (brakes, lights, tyres, steering, structure, emissions), not a full mechanical inspection of engine or gearbox internals. It is a reliability signal, not a complete measure of mechanical reliability. What this measures.
“vs expected” adjusts for age, mileage and test class, so a cherished classic and a hard-used commuter are compared fairly. How this works.
Pass rate over time
The GN400's first-time pass rate has risen 16.9 points since 2006, 64.9% to 81.8%.
Pass rate by mileage
A low-mileage GN400 passes first time 83.6% of the time; by 40k that's 82.3%.
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 GN400
| Component group | Share of defects | Defects | % of defects | vs all bikes |
|---|---|---|---|---|
| lighting and signalling |
|
93 | 40.8 | 1.9× |
| steering and suspension |
|
45 | 19.7 | 1.7× |
| lamps and reflectors |
|
25 | 11 | 1.0× |
| tyres and wheels |
|
17 | 7.5 | 1.1× |
| drive system |
|
12 | 5.3 | 1.8× |
| brakes |
|
11 | 4.8 | 0.4× |
| fuel and exhaust |
|
10 | 4.4 | 1.7× |
| reg plates and vin |
|
5 | 2.2 | 1.6× |
| body and structure |
|
5 | 2.2 | 1.9× |
| structure and attachments |
|
5 | 2.2 | 1.1× |
Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects. "vs all bikes" is how often this model's tests record a defect in the group, as a multiple of the all-bike rate.
How rivals compare
On first-time pass rate the GN400 beats 1 of its 4 closest rivals (KAWASAKI ER5, SUZUKI GS500, SUZUKI AN400).
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 GN400.
Compare with any bike
More SUZUKI models
Pass rate by registration year
Highest pass rate: 1981 (80.7%). Lowest: 1980 (69.0%). Every GN400 year compared →
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.
SUZUKI GN400 FAQ
Is the SUZUKI GN400 reliable?
The SUZUKI GN400 is less reliable than average for its class: 77.1% of its 536 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #4044 of 5428 models.
What does a GN400 fail its MOT on most?
lighting and signalling: 41% of all defects recorded against failed GN400 tests.
What is the best year of GN400 to buy used?
By first-time pass rate, 1981-registered examples do best (80.7%) and 1980 worst (69.0%). Condition and history still trump the year.
How many miles will a GN400 last?
The median GN400 shows 21,702 miles at test, and examples around 40k miles still pass 82.3% of the time, so mileage alone rarely decides the result.
Embed this bike
Free to embed on your site, blog or forum: a live Suzuki GN400 reliability card that stays up to date and links back here. More on the free API page.