Suzuki GSF 650 SK5 vs Yamaha FZS600

The Suzuki GSF 650 SK5 passes its MOT first time more often than the Yamaha FZS600: 85.5% vs 82.6%, a 2.9-point lead.

MOT reliability, side by side

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

Metric	Suzuki GSF 650 SK5	Yamaha FZS600
First-time pass rate	85.5%	82.6%
Outright fail rate	8.7%	10.6%
Vs comparable bikes (age & mileage adjusted)	+0.5 pts	-0.8 pts
Engine size	656cc	599cc
Rank among all models	#2363 of 5428	#3052 of 5428
Median miles at test	15,272	21,612
MOT tests analysed	3,330	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 GSF 650 SK5	Yamaha FZS600
Brakes	2.9%	4.5%
Lights & signalling	2.5%	3.4%
Tyres & wheels	2.8%	2.9%
Steering & suspension	1.8%	2.7%
Drive system	1.0%	0.9%
Fuel & exhaust	0.7%	1.1%
Structure & body	0.7%	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 GSF 650 SK5	Yamaha FZS600
2018	88.7%	81.3%
2019	82.9%	83.0%
2020	83.2%	83.6%
2021	86.2%	82.8%
2022	89.9%	83.6%
2023	85.0%	84.2%
2024	80.4%	83.3%
2025	74.5%	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 GSF 650 SK5	Yamaha FZS600
0k-10k miles	90.7%	89.6%
10k-20k miles	85.6%	85.5%
20k-30k miles	83.7%	81.4%
30k-40k miles	79.6%	78.7%
40k-50k miles	79.5%	76.8%
50k-60k miles	78.1%	74.7%

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

Suzuki GSF 650 SK5 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Suzuki GSF 650 SK5 or the Yamaha FZS600?

The Suzuki GSF 650 SK5 passes its MOT first time more often than the Yamaha FZS600: 85.5% vs 82.6%, a 2.9-point lead. Adjusted for age, mileage and test class, the Suzuki GSF 650 SK5 still comes out ahead: +0.5 points vs comparable bikes for the Suzuki GSF 650 SK5, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Suzuki GSF 650 SK5 fail its MOT on most?

Brakes: 2.9% of Suzuki GSF 650 SK5 MOT tests failed on it, then tyres & wheels (2.8%).

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 GSF 650 SK5 or the Yamaha FZS600?

At 50k-60k miles the Suzuki GSF 650 SK5 passes first time more often: 78.1% for the Suzuki GSF 650 SK5 vs 74.7% for the Yamaha FZS600.

SUZUKI GSF 650 SK5 85.5% pass · 3,330 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.