HONDA CB400 FOUR

408cc Petrol Class 2

#2909 of 5426 overall #464 of 921 HONDAs #135 of 205 naked bikes

83.2%

first-time pass rate

8.9%

failed outright

31,108

median miles at test

945

MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2006–2018

The CB400 FOUR's first-time pass rate has fallen 7.9 points since 2006, 84.4% to 76.5%.

Pass rate by mileage

how the CB400 FOUR's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage CB400 FOUR passes first time 86.0% of the time; by 50k that's 72.4%.

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 CB400 FOUR

failure defects by component group · advisories excluded

Component group	Defects	% of defects	vs all bikes
lighting and signalling	64	34	1.1×
brakes	48	25.5	0.9×
steering and suspension	31	16.5	0.8×
tyres and wheels	15	8	0.6×
fuel and exhaust	7	3.7	1.0×
body and structure	6	3.2	1.1×
driving controls	5	2.7	2.3×
drive system	5	2.7	0.7×
reg plates and vin	4	2.1	0.7×
lamps and reflectors	3	1.6	0.2×

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

same type, similar capacity, high test volume

On first-time pass rate the CB400 FOUR beats 2 of its 3 closest rivals (HONDA CB500, HONDA CB400, HONDA CB400N).

HONDA CB500 83.3% pass · 105k tests HONDA CB400 80.9% pass · 9,072 tests HONDA CB400N 77.5% pass · 5,366 tests

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 CB400 FOUR.

Pass rate by registration year

how each model-year cohort fares · registration year from first use date

Best year to buy used: 1975 (86.6% pass). Weakest: 1978 (82.4%).

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.

HONDA CB400 FOUR FAQ

answers computed from the data above · terms in the glossary

Is the HONDA CB400 FOUR reliable?

The HONDA CB400 FOUR is about average for its class: 83.2% of its 945 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #2909 of 5426 models.

What does a CB400 FOUR fail its MOT on most?

lighting and signalling — 34% of all defects recorded against failed CB400 FOUR tests.

What is the best year of CB400 FOUR to buy used?

By first-time pass rate, 1975-registered examples do best (86.6%) and 1978 worst (82.4%). Condition and history still trump the year.

How many miles will a CB400 FOUR last?

The median CB400 FOUR shows 31,108 miles at test, and examples around 50k miles still pass 72.4% of the time — mileage alone rarely kills one.