YAMAHA RD400C

398cc Petrol Class 2

83.8%

first-time pass rate

5.4%

failed outright

16,691

median miles at test

167

MOT tests, 2005–2025

Pass rate by mileage

how the RD400C's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage RD400C passes first time 88.4% of the time; by 20k that's 58.8%.

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 RD400C

failure defects by component group · advisories excluded

Component group	Defects	% of defects
brakes	11	61.1
steering and suspension	3	16.7
lamps and reflectors	2	11.1
steering	1	5.6
structure and attachments	1	5.6

Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.

How rivals compare

same type, similar capacity, high test volume

On first-time pass rate the RD400C beats 3 of its 4 closest rivals (KAWASAKI ER5, SUZUKI GS500, SUZUKI AN400).

KAWASAKI ER5 77.4% pass · 53.1k tests SUZUKI GS500 76.4% pass · 44.9k tests SUZUKI AN400 86.2% pass · 27.1k tests SUZUKI DR-Z400S 80.4% pass · 26.8k 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 RD400C.

Pass rate by registration year

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

Best year to buy used: 1976 (86.3% pass). Weakest: 1976 (86.3%).

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.