Ajs Model 20 vs Kawasaki ZX-6R

The Ajs Model 20 passes its MOT first time more often than the Kawasaki ZX-6R: 90.3% vs 78.1%, a 12.2-point lead.

MOT reliability, side by side

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

Metric	Ajs Model 20	Kawasaki ZX-6R
First-time pass rate	90.3%	78.1%
Outright fail rate	3.2%	14.0%
Engine size	500cc	599cc
Rank among all models	#854 of 5428	#3895 of 5428
Median miles at test	16,829	19,446
MOT tests analysed	308	173,956
Most common failure	steering and suspension	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.

Pass rate by test year

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

Test year	Ajs Model 20	Kawasaki ZX-6R
2006	100.0%	82.8%
2007	88.2%	81.0%
2009	86.1%	76.6%
2010	85.3%	76.3%
2011	88.2%	76.6%
2012	90.0%	75.4%

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	Ajs Model 20	Kawasaki ZX-6R
0k-10k miles	86.8%	86.1%
10k-20k miles	94.0%	80.6%
20k-30k miles	94.7%	75.4%
30k-40k miles	87.1%	71.8%

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

AJS MODEL 20 90.3% pass · 308 tests KAWASAKI ZX-6R 78.1% pass · 174k tests

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