YAMAHA DT125

124cc Petrol Class 1

#4977 of 5426 overall #390 of 409 YAMAHAs #504 of 734 commuter bikes

65.8%

first-time pass rate

23.3%

failed outright

14,546

median miles at test

39.1k

MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2005–2025

The DT125's first-time pass rate has risen 10.4 points since 2005, 69.8% to 80.2%.

Pass rate by mileage

how the DT125's first-time pass rate falls with the odometer · class average 73.4%

A low-mileage DT125 passes first time 72.9% of the time; by 50k that's 64.8%.

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 DT125

failure defects by component group · advisories excluded

Component group	Defects	% of defects	vs all bikes
lighting and signalling	10,992	34.2	3.4×
brakes	4,849	15.1	2.0×
steering and suspension	4,565	14.2	2.6×
tyres and wheels	3,563	11.1	3.3×
drive system	2,786	8.7	6.5×
lamps and reflectors	1,752	5.5	1.4×
reg plates and vin	1,120	3.5	4.3×
body and structure	1,104	3.4	4.2×
fuel and exhaust	754	2.3	2.2×
structure and attachments	633	2	1.5×

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 DT125 beats 0 of its 4 closest rivals (YAMAHA YBR 125, HONDA CG125, HONDA CBF125).

YAMAHA YBR 125 71.0% pass · 125k tests HONDA CG125 72.2% pass · 89.3k tests HONDA CBF125 73.3% pass · 84.4k tests GILERA RUNNER 70.8% pass · 69.9k 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 DT125.

Pass rate by registration year

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

Best year to buy used: 2020 (90.2% pass). Weakest: 1994 (59.8%).

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.

YAMAHA DT125 FAQ

answers computed from the data above · terms in the glossary

Is the YAMAHA DT125 reliable?

The YAMAHA DT125 is less reliable than average for its class: 65.8% of its 39,054 MOT tests (2005–2025) passed first time, against a class average of 73.4%. That ranks it #4977 of 5426 models.

What does a DT125 fail its MOT on most?

lighting and signalling — 34% of all defects recorded against failed DT125 tests.

What is the best year of DT125 to buy used?

By first-time pass rate, 2020-registered examples do best (90.2%) and 1994 worst (59.8%). Condition and history still trump the year.

How many miles will a DT125 last?

The median DT125 shows 14,546 miles at test, and examples around 50k miles still pass 64.8% of the time — mileage alone rarely kills one.