Ajs 31CSR vs Suzuki GSF600

The Ajs 31CSR passes its MOT first time more often than the Suzuki GSF600: 91.7% vs 77.3%, a 14.4-point lead.

MOT reliability, side by side

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

Metric	Ajs 31CSR	Suzuki GSF600
First-time pass rate	91.7%	77.3%
Outright fail rate	2.0%	14.2%
Engine size	650cc	599cc
Rank among all models	#524 of 5428	#4013 of 5428
Median miles at test	21,958	21,080
MOT tests analysed	254	143,023
Most common failure	lighting and signalling	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.

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Ajs 31CSR	Suzuki GSF600
0k-10k miles	94.9%	86.8%
10k-20k miles	92.1%	80.1%
20k-30k miles	91.7%	75.2%
30k-40k miles	84.3%	71.3%

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

AJS 31CSR 91.7% pass · 254 tests SUZUKI GSF600 77.3% pass · 143k tests

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