BIKERELIABILITY Reg check
League table/ KTM 640 LC4-E/vs Suzuki GSF600
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

KTM 640 LC4-E vs Suzuki GSF600

The KTM 640 LC4-E passes its MOT first time more often than the Suzuki GSF600: 80.6% vs 77.3%, a 3.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric KTM 640 LC4-E Suzuki GSF600
First-time pass rate 80.6% 77.3%
Outright fail rate 10.0% 14.2%
Vs comparable bikes (age & mileage adjusted) -6.8 pts -6.1 pts
Engine size 625cc 599cc
Rank among all models #3459 of 5428 #4013 of 5428
Median miles at test 7,836 21,080
MOT tests analysed 8,115 143,023
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 KTM 640 LC4-E Suzuki GSF600
Lights & signalling 6.0% 6.7%
Brakes 1.5% 6.1%
Steering & suspension 2.4% 3.6%
Tyres & wheels 2.4% 3.3%
Drive system 1.0% 1.4%
Structure & body 0.6% 1.5%
Fuel & exhaust 0.5% 1.2%

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 KTM 640 LC4-E Suzuki GSF600
2018 83.5% 77.7%
2019 82.2% 76.7%
2020 83.6% 77.8%
2021 79.5% 76.8%
2022 79.6% 78.1%
2023 83.8% 78.2%
2024 88.6% 78.9%
2025 82.5% 79.6%

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 KTM 640 LC4-E Suzuki GSF600
0k-10k miles 81.9% 86.8%
10k-20k miles 78.9% 80.1%
20k-30k miles 73.2% 75.2%
30k-40k miles 85.4% 71.3%

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

KTM 640 LC4-E vs Suzuki GSF600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the KTM 640 LC4-E or the Suzuki GSF600?

The KTM 640 LC4-E passes its MOT first time more often than the Suzuki GSF600: 80.6% vs 77.3%, a 3.3-point lead. Adjusted for age, mileage and test class the two are level (-6.8 vs -6.1 points against comparable bikes), so the raw gap is mostly down to how old and how used each fleet is. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the KTM 640 LC4-E fail its MOT on most?

Lights & signalling: 6.0% of KTM 640 LC4-E MOT tests failed on it, then steering & suspension (2.4%).

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%).

Which holds up better at high mileage, the KTM 640 LC4-E or the Suzuki GSF600?

At 30k-40k miles the KTM 640 LC4-E passes first time more often: 85.4% for the KTM 640 LC4-E vs 71.3% for the Suzuki GSF600.

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