Suzuki GSX 650 FK8 vs Yamaha FZS600

The Suzuki GSX 650 FK8 passes its MOT first time more often than the Yamaha FZS600: 87.6% vs 82.6%, a 5.0-point lead.

MOT reliability, side by side

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

Metric	Suzuki GSX 650 FK8	Yamaha FZS600
First-time pass rate	87.6%	82.6%
Outright fail rate	6.7%	10.6%
Vs comparable bikes (age & mileage adjusted)	+2.0 pts	-0.8 pts
Engine size	644cc	599cc
Rank among all models	#1725 of 5428	#3052 of 5428
Median miles at test	13,427	21,612
MOT tests analysed	7,404	136,558
Most common failure	brakes	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	Suzuki GSX 650 FK8	Yamaha FZS600
Brakes	2.2%	4.5%
Lights & signalling	2.4%	3.4%
Tyres & wheels	2.4%	2.9%
Steering & suspension	1.1%	2.7%
Structure & body	0.9%	1.1%
Drive system	0.5%	0.9%
Fuel & exhaust	0.1%	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	Suzuki GSX 650 FK8	Yamaha FZS600
2018	88.8%	81.3%
2019	85.2%	83.0%
2020	86.9%	83.6%
2021	87.2%	82.8%
2022	85.6%	83.6%
2023	86.3%	84.2%
2024	84.4%	83.3%
2025	84.6%	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	Suzuki GSX 650 FK8	Yamaha FZS600
0k-10k miles	92.6%	89.6%
10k-20k miles	88.5%	85.5%
20k-30k miles	82.6%	81.4%
30k-40k miles	77.7%	78.7%
40k-50k miles	76.9%	76.8%
50k-60k miles	85.3%	74.7%

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

Suzuki GSX 650 FK8 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Suzuki GSX 650 FK8 or the Yamaha FZS600?

The Suzuki GSX 650 FK8 passes its MOT first time more often than the Yamaha FZS600: 87.6% vs 82.6%, a 5.0-point lead. Adjusted for age, mileage and test class, the Suzuki GSX 650 FK8 still comes out ahead: +2.0 points vs comparable bikes for the Suzuki GSX 650 FK8, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Suzuki GSX 650 FK8 fail its MOT on most?

Lights & signalling: 2.4% of Suzuki GSX 650 FK8 MOT tests failed on it, then tyres & wheels (2.4%).

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 Suzuki GSX 650 FK8 or the Yamaha FZS600?

At 50k-60k miles the Suzuki GSX 650 FK8 passes first time more often: 85.3% for the Suzuki GSX 650 FK8 vs 74.7% for the Yamaha FZS600.

SUZUKI GSX 650 FK8 87.6% pass · 7,404 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.