Bsa B25 vs Yamaha WR250F

The Bsa B25 passes its MOT first time more often than the Yamaha WR250F: 88.5% vs 78.0%, a 10.5-point lead.

MOT reliability, side by side

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

Metric	Bsa B25	Yamaha WR250F
First-time pass rate	88.5%	78.0%
Outright fail rate	4.1%	12.8%
Vs comparable bikes (age & mileage adjusted)	+4.6 pts	-10.7 pts
Engine size	250cc	249cc
Rank among all models	#1449 of 5428	#3913 of 5428
Median miles at test	9,304	3,018
MOT tests analysed	886	10,465
Most common failure	lighting and signalling	lighting and signalling

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	Bsa B25	Yamaha WR250F
Lights & signalling	1.9%	8.2%
Steering & suspension	1.8%	5.1%
Tyres & wheels	0.3%	3.0%
Brakes	0.7%	2.2%
Structure & body	0.5%	0.5%
Drive system	0.2%	0.7%
Fuel & exhaust	0.2%	0.4%

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	Bsa B25	Yamaha WR250F
2010	96.6%	75.3%
2011	81.8%	76.7%
2012	85.9%	76.5%
2013	87.2%	75.7%
2014	91.0%	77.9%
2015	89.7%	77.3%
2016	85.1%	78.9%
2017	86.8%	80.3%

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	Bsa B25	Yamaha WR250F
0k-10k miles	88.3%	78.1%
10k-20k miles	86.7%	77.3%
20k-30k miles	91.2%	67.9%

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

Bsa B25 vs Yamaha WR250F FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Bsa B25 or the Yamaha WR250F?

The Bsa B25 passes its MOT first time more often than the Yamaha WR250F: 88.5% vs 78.0%, a 10.5-point lead. Adjusted for age, mileage and test class, the Bsa B25 still comes out ahead: +4.6 points vs comparable bikes for the Bsa B25, -10.7 for the Yamaha WR250F. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Bsa B25 fail its MOT on most?

Lights & signalling: 1.9% of Bsa B25 MOT tests failed on it, then steering & suspension (1.8%).

What does the Yamaha WR250F fail its MOT on most?

Lights & signalling: 8.2% of Yamaha WR250F MOT tests failed on it, then steering & suspension (5.1%).

Which holds up better at high mileage, the Bsa B25 or the Yamaha WR250F?

At 20k-30k miles the Bsa B25 passes first time more often: 91.2% for the Bsa B25 vs 67.9% for the Yamaha WR250F.

BSA B25 88.5% pass · 886 tests YAMAHA WR250F 78.0% pass · 10.5k tests

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