BIKERELIABILITY
MOT DATA · GREAT BRITAIN · 2005–2025
Model report · 2005–2025

YAMAHA YZ

125cc Petrol Class 1
81.4%
first-time pass rate
12.1%
failed outright
659
median miles at test
1,650
MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2017–2025

The YZ's first-time pass rate has risen 10.3 points since 2017, 78.1% to 88.4%.

74%83%91%2017: 78.1% pass (64 tests)2018: 77.5% pass (80 tests)2019: 77.0% pass (87 tests)2020: 77.3% pass (128 tests)2021: 82.5% pass (200 tests)2022: 83.8% pass (234 tests)2023: 79.1% pass (235 tests)2024: 82.8% pass (221 tests)2025: 88.4% pass (224 tests)20172025

What fails on a YZ

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects vs all bikes
suspension
97 17.8 5.7×
lamps and reflectors
82 15 1.8×
brakes
66 12.1 0.7×
tyres
63 11.5 3.5×
structure and attachments
56 10.3 3.5×
audible warning (Horn)
48 8.8 15.9×
steering and suspension
41 7.5 0.6×
Identification of the vehicle
34 6.2 8.7×
lighting and signalling
33 6 0.4×
steering
26 4.8 3.5×

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

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 YZ.

Pass rate by registration year

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

Best year to buy used: 2016 (87.0% pass). Weakest: 2020 (69.8%).

66%78%90%1999: 81.9% pass (72 tests)2000: 85.7% pass (56 tests)2001: 85.1% pass (74 tests)2003: 79.7% pass (74 tests)2004: 71.4% pass (91 tests)2005: 84.3% pass (89 tests)2006: 86.8% pass (76 tests)2007: 86.9% pass (84 tests)2015: 81.7% pass (60 tests)2016: 87.0% pass (54 tests)2017: 82.9% pass (105 tests)2018: 77.8% pass (81 tests)2019: 86.8% pass (114 tests)2020: 69.8% pass (86 tests)2021: 82.6% pass (69 tests)199920072021

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 YZ FAQ

answers computed from the data above · terms in the glossary

Is the YAMAHA YZ reliable?

The YAMAHA YZ is more reliable than average for its class: 81.4% of its 1,650 MOT tests (2005–2025) passed first time, against a class average of 73.4%. That ranks it #3291 of 5426 models.

What does a YZ fail its MOT on most?

suspension — 18% of all defects recorded against failed YZ tests.

What is the best year of YZ to buy used?

By first-time pass rate, 2016-registered examples do best (87.0%) and 2020 worst (69.8%). Condition and history still trump the year.