Kaisar KS 125-23 vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the Kaisar KS 125-23: 71.0% vs 46.7%, a 24.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	Kaisar KS 125-23	Yamaha YBR 125
First-time pass rate	46.7%	71.0%
Outright fail rate	41.7%	17.1%
Vs comparable bikes (age & mileage adjusted)	-27.9 pts	-1.1 pts
Engine size	124cc	124cc
Rank among all models	#5414 of 5428	#4664 of 5428
Median miles at test	5,604	10,652
MOT tests analysed	655	124,897
Most common failure	lighting and signalling	brakes

First-time outcomes on normal tests, 2005–2025. "Most common failure" is the component group with the most recorded defects on failed tests. Read pass rates against test counts: a smaller sample is noisier. Source: DVSA anonymised MOT results.

"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.

What fails, side by side

share of each bike's MOT tests that failed on the component · lower is better

Component	Kaisar KS 125-23	Yamaha YBR 125
Lights & signalling	32.7%	8.5%
Steering & suspension	22.4%	6.5%
Brakes	16.8%	5.9%
Tyres & wheels	11.5%	4.4%
Drive system	11.8%	2.9%
Structure & body	9.8%	3.8%
Fuel & exhaust	6.1%	0.6%

A test that fails on two components counts once in each. Component links go to the bikes most likely to fail on it.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested

Test year	Kaisar KS 125-23	Yamaha YBR 125
2010	54.5%	71.4%
2011	48.5%	69.1%
2012	53.0%	69.1%
2013	40.2%	69.5%
2014	37.6%	70.0%
2015	48.4%	71.2%
2016	42.4%	71.3%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Kaisar KS 125-23	Yamaha YBR 125
0k-10k miles	49.0%	76.8%
10k-20k miles	38.6%	67.4%

Bands with fewer than 30 tests for either bike are left out.

Kaisar KS 125-23 vs Yamaha YBR 125 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Kaisar KS 125-23 or the Yamaha YBR 125?

The Yamaha YBR 125 passes its MOT first time more often than the Kaisar KS 125-23: 71.0% vs 46.7%, a 24.3-point lead. Adjusted for age, mileage and test class, the Yamaha YBR 125 still comes out ahead: -27.9 points vs comparable bikes for the Kaisar KS 125-23, -1.1 for the Yamaha YBR 125. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Kaisar KS 125-23 fail its MOT on most?

Lights & signalling: 32.7% of Kaisar KS 125-23 MOT tests failed on it, then steering & suspension (22.4%).

What does the Yamaha YBR 125 fail its MOT on most?

Lights & signalling: 8.5% of Yamaha YBR 125 MOT tests failed on it, then steering & suspension (6.5%).

KAISAR KS 125-23 46.7% pass · 655 tests YAMAHA YBR 125 71.0% pass · 125k tests

See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.