BIKERELIABILITY Reg check
League table/ Kawasaki Ex/vs Yamaha FZS600
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Kawasaki Ex vs Yamaha FZS600

The Kawasaki Ex passes its MOT first time more often than the Yamaha FZS600: 85.0% vs 82.6%, a 2.4-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Kawasaki Ex Yamaha FZS600
First-time pass rate 85.0% 82.6%
Outright fail rate 8.0% 10.6%
Vs comparable bikes (age & mileage adjusted) -2.0 pts -0.8 pts
Engine size 649cc 599cc
Rank among all models #2491 of 5428 #3052 of 5428
Median miles at test 9,625 21,612
MOT tests analysed 12,054 136,558
Most common failure lamps and reflectors 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.

"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 Kawasaki Ex Yamaha FZS600
Lights & signalling 3.7% 3.4%
Brakes 2.3% 4.5%
Tyres & wheels 2.3% 2.9%
Steering & suspension 1.7% 2.7%
Structure & body 1.5% 1.1%
Drive system 0.2% 0.9%
Fuel & exhaust 0.0% 1.1%

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 Kawasaki Ex Yamaha FZS600
2018 85.7% 81.3%
2019 84.8% 83.0%
2020 84.3% 83.6%
2021 84.0% 82.8%
2022 86.2% 83.6%
2023 85.6% 84.2%
2024 85.3% 83.3%
2025 85.1% 84.0%

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 Kawasaki Ex Yamaha FZS600
0k-10k miles 89.7% 89.6%
10k-20k miles 83.1% 85.5%
20k-30k miles 75.4% 81.4%
30k-40k miles 71.9% 78.7%
40k-50k miles 67.5% 76.8%
50k-60k miles 74.5% 74.7%

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

Kawasaki Ex vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Kawasaki Ex or the Yamaha FZS600?

The Kawasaki Ex passes its MOT first time more often than the Yamaha FZS600: 85.0% vs 82.6%, a 2.4-point lead. Adjusted for age, mileage and test class, the Yamaha FZS600 still comes out ahead: -2.0 points vs comparable bikes for the Kawasaki Ex, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Kawasaki Ex fail its MOT on most?

Lights & signalling: 3.7% of Kawasaki Ex MOT tests failed on it, then brakes (2.3%).

What does the Yamaha FZS600 fail its MOT on most?

Brakes: 4.5% of Yamaha FZS600 MOT tests failed on it, then lights & signalling (3.4%).

Which holds up better at high mileage, the Kawasaki Ex or the Yamaha FZS600?

They are level: at 50k-60k miles the Kawasaki Ex passes 74.5% first time and the Yamaha FZS600 74.7%.

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