MZ ETZ301 vs Yamaha RD350

The Yamaha RD350 passes its MOT first time more often than the MZ ETZ301: 86.3% vs 84.1%, a 2.2-point lead.

MOT reliability, side by side

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

Metric	MZ ETZ301	Yamaha RD350
First-time pass rate	84.1%	86.3%
Outright fail rate	8.0%	6.6%
Vs comparable bikes (age & mileage adjusted)	+2.4 pts	+2.4 pts
Engine size	291cc	347cc
Rank among all models	#2721 of 5428	#2120 of 5428
Median miles at test	31,240	23,256
MOT tests analysed	675	19,574
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 ETZ301	Yamaha RD350
Lights & signalling	5.2%	3.2%
Brakes	2.4%	2.7%
Steering & suspension	1.5%	2.5%
Tyres & wheels	1.8%	0.9%
Fuel & exhaust	0.6%	0.4%
Drive system	0.1%	0.5%
Structure & body	0.1%	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	MZ ETZ301	Yamaha RD350
2008	74.5%	79.7%
2009	75.5%	80.6%
2010	82.6%	81.9%
2011	89.2%	82.2%
2012	78.9%	84.7%
2013	87.8%	85.8%
2014	91.2%	86.6%
2015	86.7%	85.3%

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	MZ ETZ301	Yamaha RD350
0k-10k miles	88.2%	88.9%
10k-20k miles	88.2%	87.5%
20k-30k miles	87.7%	85.5%
30k-40k miles	87.7%	85.3%
40k-50k miles	75.8%	83.7%
50k-60k miles	79.3%	83.0%

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

MZ ETZ301 vs Yamaha RD350 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the MZ ETZ301 or the Yamaha RD350?

The Yamaha RD350 passes its MOT first time more often than the MZ ETZ301: 86.3% vs 84.1%, a 2.2-point lead. Adjusted for age, mileage and test class the two are level (+2.4 vs +2.4 points against comparable bikes), so the raw gap is mostly down to how old and how used each fleet is. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the MZ ETZ301 fail its MOT on most?

Lights & signalling: 5.2% of MZ ETZ301 MOT tests failed on it, then brakes (2.4%).

What does the Yamaha RD350 fail its MOT on most?

Lights & signalling: 3.2% of Yamaha RD350 MOT tests failed on it, then brakes (2.7%).

Which holds up better at high mileage, the MZ ETZ301 or the Yamaha RD350?

At 50k-60k miles the Yamaha RD350 passes first time more often: 79.3% for the MZ ETZ301 vs 83.0% for the Yamaha RD350.

MZ ETZ301 84.1% pass · 675 tests YAMAHA RD350 86.3% pass · 19.6k tests

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