Suzuki GSF600 vs Yamaha FZ6

The Yamaha FZ6 passes its MOT first time more often than the Suzuki GSF600: 85.2% vs 77.3%, a 7.9-point lead.

MOT reliability, side by side

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

Metric	Suzuki GSF600	Yamaha FZ6
First-time pass rate	77.3%	85.2%
Outright fail rate	14.2%	7.8%
Vs comparable bikes (age & mileage adjusted)	-6.1 pts	+0.3 pts
Engine size	599cc	599cc
Rank among all models	#4013 of 5428	#2445 of 5428
Median miles at test	21,080	15,484
MOT tests analysed	143,023	67,149
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 GSF600	Yamaha FZ6
Lights & signalling	6.7%	3.1%
Brakes	6.1%	2.1%
Steering & suspension	3.6%	2.4%
Tyres & wheels	3.3%	2.3%
Structure & body	1.5%	0.6%
Drive system	1.4%	0.5%
Fuel & exhaust	1.2%	0.1%

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 GSF600	Yamaha FZ6
2018	77.7%	84.5%
2019	76.7%	83.4%
2020	77.8%	82.8%
2021	76.8%	82.9%
2022	78.1%	84.0%
2023	78.2%	82.6%
2024	78.9%	83.6%
2025	79.6%	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 GSF600	Yamaha FZ6
0k-10k miles	86.8%	91.1%
10k-20k miles	80.1%	86.1%
20k-30k miles	75.2%	81.5%
30k-40k miles	71.3%	78.7%
40k-50k miles	69.4%	77.9%
50k-60k miles	68.3%	77.0%

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

Suzuki GSF600 vs Yamaha FZ6 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Suzuki GSF600 or the Yamaha FZ6?

The Yamaha FZ6 passes its MOT first time more often than the Suzuki GSF600: 85.2% vs 77.3%, a 7.9-point lead. Adjusted for age, mileage and test class, the Yamaha FZ6 still comes out ahead: -6.1 points vs comparable bikes for the Suzuki GSF600, +0.3 for the Yamaha FZ6. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Suzuki GSF600 fail its MOT on most?

Lights & signalling: 6.7% of Suzuki GSF600 MOT tests failed on it, then brakes (6.1%).

What does the Yamaha FZ6 fail its MOT on most?

Lights & signalling: 3.1% of Yamaha FZ6 MOT tests failed on it, then steering & suspension (2.4%).

Which holds up better at high mileage, the Suzuki GSF600 or the Yamaha FZ6?

At 50k-60k miles the Yamaha FZ6 passes first time more often: 68.3% for the Suzuki GSF600 vs 77.0% for the Yamaha FZ6.

SUZUKI GSF600 77.3% pass · 143k tests YAMAHA FZ6 85.2% pass · 67.1k tests

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