BIKERELIABILITY Reg check
League table/ Suzuki GSF600S/vs Kawasaki ZX-6R
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Suzuki GSF600S vs Kawasaki ZX-6R

The Suzuki GSF600S passes its MOT first time more often than the Kawasaki ZX-6R: 78.4% vs 78.1%, a 0.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Suzuki GSF600S Kawasaki ZX-6R
First-time pass rate 78.4% 78.1%
Outright fail rate 13.6% 14.0%
Vs comparable bikes (age & mileage adjusted) -5.3 pts -5.8 pts
Engine size 599cc 599cc
Rank among all models #3855 of 5428 #3895 of 5428
Median miles at test 19,671 19,446
MOT tests analysed 66,871 173,956
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.

"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 Suzuki GSF600S Kawasaki ZX-6R
Lights & signalling 5.7% 6.1%
Brakes 5.9% 5.2%
Steering & suspension 3.3% 4.6%
Tyres & wheels 3.4% 3.6%
Drive system 1.5% 1.0%
Fuel & exhaust 1.3% 0.8%
Structure & body 0.9% 1.2%

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 Suzuki GSF600S Kawasaki ZX-6R
2013 76.5% 75.5%
2014 75.8% 76.4%
2015 77.3% 76.7%
2016 77.8% 77.7%
2017 77.7% 77.1%
2018 77.4% 78.5%
2019 76.5% 78.5%
2020 78.0% 78.1%

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 Suzuki GSF600S Kawasaki ZX-6R
0k-10k miles 87.7% 86.1%
10k-20k miles 81.2% 80.6%
20k-30k miles 75.9% 75.4%
30k-40k miles 70.3% 71.8%
40k-50k miles 70.1% 69.5%
50k-60k miles 68.6% 69.0%

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

Suzuki GSF600S vs Kawasaki ZX-6R FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Suzuki GSF600S or the Kawasaki ZX-6R?

The Suzuki GSF600S passes its MOT first time more often than the Kawasaki ZX-6R: 78.4% vs 78.1%, a 0.3-point lead. Adjusted for age, mileage and test class the two are level (-5.3 vs -5.8 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 Suzuki GSF600S fail its MOT on most?

Brakes: 5.9% of Suzuki GSF600S MOT tests failed on it, then lights & signalling (5.7%).

What does the Kawasaki ZX-6R fail its MOT on most?

Lights & signalling: 6.1% of Kawasaki ZX-6R MOT tests failed on it, then brakes (5.2%).

Which holds up better at high mileage, the Suzuki GSF600S or the Kawasaki ZX-6R?

They are level: at 50k-60k miles the Suzuki GSF600S passes 68.6% first time and the Kawasaki ZX-6R 69.0%.

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