Siamoto Favourite vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the Siamoto Favourite: 71.0% vs 69.2%, a 1.8-point lead.

MOT reliability, side by side

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

Metric	Siamoto Favourite	Yamaha YBR 125
First-time pass rate	69.2%	71.0%
Outright fail rate	23.7%	17.1%
Vs comparable bikes (age & mileage adjusted)	-8.2 pts	-1.1 pts
Engine size	125cc	124cc
Rank among all models	#4794 of 5428	#4664 of 5428
Median miles at test	2,916	10,652
MOT tests analysed	393	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.

Pass rate by test year

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

Test year	Siamoto Favourite	Yamaha YBR 125
2008	70.4%	71.1%
2009	70.4%	70.7%
2010	66.7%	71.4%
2011	76.7%	69.1%

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

SIAMOTO FAVOURITE 69.2% pass · 393 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.