MZ ETZ251 vs Yamaha WR250F

The MZ ETZ251 passes its MOT first time more often than the Yamaha WR250F: 85.7% vs 78.0%, a 7.7-point lead.

MOT reliability, side by side

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

Metric	MZ ETZ251	Yamaha WR250F
First-time pass rate	85.7%	78.0%
Outright fail rate	7.0%	12.8%
Vs comparable bikes (age & mileage adjusted)	+3.2 pts	-10.7 pts
Engine size	243cc	249cc
Rank among all models	#2308 of 5428	#3913 of 5428
Median miles at test	26,720	3,018
MOT tests analysed	1,621	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	MZ ETZ251	Yamaha WR250F
Lights & signalling	3.3%	8.2%
Steering & suspension	1.9%	5.1%
Brakes	3.0%	2.2%
Tyres & wheels	1.4%	3.0%
Fuel & exhaust	0.4%	0.4%
Drive system	0%	0.7%
Structure & body	0.1%	0.5%

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	MZ ETZ251	Yamaha WR250F
2017	89.6%	80.3%
2018	83.9%	79.2%
2019	92.5%	77.2%
2020	95.0%	82.5%
2021	92.5%	80.4%
2022	95.5%	76.2%
2023	95.1%	82.1%
2025	92.3%	81.6%

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	MZ ETZ251	Yamaha WR250F
0k-10k miles	86.6%	78.1%
10k-20k miles	84.7%	77.3%
20k-30k miles	86.7%	67.9%

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

MZ ETZ251 vs Yamaha WR250F FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the MZ ETZ251 or the Yamaha WR250F?

The MZ ETZ251 passes its MOT first time more often than the Yamaha WR250F: 85.7% vs 78.0%, a 7.7-point lead. Adjusted for age, mileage and test class, the MZ ETZ251 still comes out ahead: +3.2 points vs comparable bikes for the MZ ETZ251, -10.7 for the Yamaha WR250F. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the MZ ETZ251 fail its MOT on most?

Lights & signalling: 3.3% of MZ ETZ251 MOT tests failed on it, then brakes (3.0%).

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 MZ ETZ251 or the Yamaha WR250F?

At 20k-30k miles the MZ ETZ251 passes first time more often: 86.7% for the MZ ETZ251 vs 67.9% for the Yamaha WR250F.

MZ ETZ251 85.7% pass · 1,621 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.