Bsa C12 vs Yamaha YP250

The Bsa C12 passes its MOT first time more often than the Yamaha YP250: 91.7% vs 82.5%, a 9.2-point lead.

MOT reliability, side by side

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

Metric	Bsa C12	Yamaha YP250
First-time pass rate	91.7%	82.5%
Outright fail rate	4.7%	12.3%
Engine size	250cc	249cc
Rank among all models	#524 of 5428	#3073 of 5428
Median miles at test	12,950	15,613
MOT tests analysed	553	12,433
Most common failure	steering and suspension	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.

What fails, side by side

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

Component	Bsa C12	Yamaha YP250
Steering & suspension	2.5%	5.0%
Brakes	1.1%	5.3%
Tyres & wheels	1.4%	3.8%
Lights & signalling	1.4%	2.5%
Structure & body	0.5%	0.5%
Fuel & exhaust	0%	0.8%

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 C12	Yamaha YP250
2006	93.4%	86.7%
2007	88.4%	79.8%
2008	91.0%	80.8%
2009	91.0%	81.8%
2010	94.3%	81.3%
2011	88.9%	80.4%
2012	91.4%	83.9%

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 C12	Yamaha YP250
0k-10k miles	91.4%	88.6%
10k-20k miles	96.0%	82.5%
20k-30k miles	88.0%	78.6%
30k-40k miles	91.2%	77.0%
40k-50k miles	88.2%	71.9%
50k-60k miles	94.4%	84.7%

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

Bsa C12 vs Yamaha YP250 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Bsa C12 or the Yamaha YP250?

The Bsa C12 passes its MOT first time more often than the Yamaha YP250: 91.7% vs 82.5%, a 9.2-point lead. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Bsa C12 fail its MOT on most?

Steering & suspension: 2.5% of Bsa C12 MOT tests failed on it, then tyres & wheels (1.4%).

What does the Yamaha YP250 fail its MOT on most?

Brakes: 5.3% of Yamaha YP250 MOT tests failed on it, then steering & suspension (5.0%).

Which holds up better at high mileage, the Bsa C12 or the Yamaha YP250?

At 50k-60k miles the Bsa C12 passes first time more often: 94.4% for the Bsa C12 vs 84.7% for the Yamaha YP250.

BSA C12 91.7% pass · 553 tests YAMAHA YP250 82.5% pass · 12.4k tests

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