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

YAMAHA QT50

49cc Petrol Class 1
82.0%
first-time pass rate
12.1%
failed outright
4,996
median miles at test
1,119
MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2005–2021

The QT50's first-time pass rate has risen 9.3 points since 2005, 79.3% to 88.6%.

67%83%99%2005: 79.3% pass (58 tests)2006: 78.1% pass (146 tests)2007: 82.3% pass (113 tests)2008: 77.3% pass (97 tests)2009: 80.7% pass (83 tests)2010: 85.5% pass (69 tests)2011: 71.9% pass (64 tests)2012: 80.4% pass (56 tests)2013: 81.8% pass (55 tests)2014: 91.4% pass (58 tests)2015: 82.9% pass (41 tests)2016: 83.3% pass (36 tests)2017: 84.1% pass (44 tests)2018: 83.3% pass (30 tests)2020: 93.3% pass (30 tests)2021: 88.6% pass (35 tests)20052021

What fails on a QT50

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects vs all bikes
lighting and signalling
250 61.1 2.1×
brakes
64 15.6 0.9×
tyres and wheels
30 7.3 1.0×
steering and suspension
30 7.3 0.7×
lamps and reflectors
13 3.2 0.5×
fuel and exhaust
9 2.2 0.9×
Items Not Tested
6 1.5 1.0×
tyres
3 0.7 0.3×
body and structure
3 0.7 0.4×
wheels
1 0.2 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 QT50 beats 4 of its 4 closest rivals (PEUGEOT SPEEDFIGHT, PIAGGIO ZIP, PIAGGIO NRG).

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 QT50.

Pass rate by registration year

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

Best year to buy used: 1991 (89.6% pass). Weakest: 1987 (73.6%).

70%82%93%1982: 86.2% pass (138 tests)1986: 81.9% pass (155 tests)1987: 73.6% pass (121 tests)1989: 77.4% pass (93 tests)1990: 84.4% pass (167 tests)1991: 89.6% pass (134 tests)1992: 80.7% pass (114 tests)1993: 79.2% pass (77 tests)198219901993

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 QT50 FAQ

answers computed from the data above · terms in the glossary

Is the YAMAHA QT50 reliable?

The YAMAHA QT50 is more reliable than average for its class: 82.0% of its 1,119 MOT tests (2005–2025) passed first time, against a class average of 73.4%. That ranks it #3181 of 5426 models.

What does a QT50 fail its MOT on most?

lighting and signalling — 61% of all defects recorded against failed QT50 tests.

What is the best year of QT50 to buy used?

By first-time pass rate, 1991-registered examples do best (89.6%) and 1987 worst (73.6%). Condition and history still trump the year.