BIKERELIABILITY Reg check
League table/ Ajs 20/vs Kawasaki ZX-6R
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Ajs 20 vs Kawasaki ZX-6R

The Ajs 20 passes its MOT first time more often than the Kawasaki ZX-6R: 93.9% vs 78.1%, a 15.8-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ajs 20 Kawasaki ZX-6R
First-time pass rate 93.9% 78.1%
Outright fail rate 0.8% 14.0%
Engine size 500cc 599cc
Rank among all models #183 of 5428 #3895 of 5428
Median miles at test 13,470 19,446
MOT tests analysed 247 173,956
Most common failure brakes 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 20 Kawasaki ZX-6R
2006 97.1% 82.8%
2007 96.8% 81.0%
2008 93.5% 78.4%
2009 84.4% 76.6%
2010 90.0% 76.3%

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 Ajs 20 Kawasaki ZX-6R
0k-10k miles 94.6% 86.1%
10k-20k miles 100.0% 80.6%
20k-30k miles 87.9% 75.4%

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

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