Kawasaki ZX636 vs Yamaha FZS600

The Yamaha FZS600 passes its MOT first time more often than the Kawasaki ZX636: 82.6% vs 77.5%, a 5.1-point lead.

MOT reliability, side by side

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

Metric	Kawasaki ZX636	Yamaha FZS600
First-time pass rate	77.5%	82.6%
Outright fail rate	12.5%	10.6%
Vs comparable bikes (age & mileage adjusted)	-8.2 pts	-0.8 pts
Engine size	636cc	599cc
Rank among all models	#3977 of 5428	#3052 of 5428
Median miles at test	13,196	21,612
MOT tests analysed	1,596	136,558
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.

"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 ZX636	Yamaha FZS600
Lights & signalling	6.6%	3.4%
Brakes	2.6%	4.5%
Tyres & wheels	3.3%	2.9%
Steering & suspension	2.9%	2.7%
Structure & body	1.0%	1.1%
Fuel & exhaust	0.6%	1.1%
Drive system	0.6%	0.9%

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 ZX636	Yamaha FZS600
2018	80.6%	81.3%
2019	73.4%	83.0%
2020	76.6%	83.6%
2021	82.8%	82.8%
2022	74.6%	83.6%
2023	84.6%	84.2%
2024	77.8%	83.3%
2025	79.1%	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 ZX636	Yamaha FZS600
0k-10k miles	83.2%	89.6%
10k-20k miles	76.1%	85.5%
20k-30k miles	74.6%	81.4%
30k-40k miles	67.9%	78.7%
40k-50k miles	75.0%	76.8%

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

Kawasaki ZX636 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Kawasaki ZX636 or the Yamaha FZS600?

The Yamaha FZS600 passes its MOT first time more often than the Kawasaki ZX636: 82.6% vs 77.5%, a 5.1-point lead. Adjusted for age, mileage and test class, the Yamaha FZS600 still comes out ahead: -8.2 points vs comparable bikes for the Kawasaki ZX636, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Kawasaki ZX636 fail its MOT on most?

Lights & signalling: 6.6% of Kawasaki ZX636 MOT tests failed on it, then tyres & wheels (3.3%).

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 ZX636 or the Yamaha FZS600?

At 40k-50k miles the Yamaha FZS600 passes first time more often: 75.0% for the Kawasaki ZX636 vs 76.8% for the Yamaha FZS600.

KAWASAKI ZX636 77.5% pass · 1,596 tests YAMAHA FZS600 82.6% pass · 137k tests

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