BIKERELIABILITY Reg check
League table/ Yamaha RD/vs Suzuki AN400
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Yamaha RD vs Suzuki AN400

The Suzuki AN400 passes its MOT first time more often than the Yamaha RD: 86.2% vs 86.0%, a 0.2-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Yamaha RD Suzuki AN400
First-time pass rate 86.0% 86.2%
Outright fail rate 7.7% 9.8%
Vs comparable bikes (age & mileage adjusted) +2.1 pts +1.3 pts
Engine size 347cc 385cc
Rank among all models #2197 of 5428 #2148 of 5428
Median miles at test 21,449 15,861
MOT tests analysed 2,258 27,056
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 Yamaha RD Suzuki AN400
Brakes 3.0% 4.4%
Lights & signalling 3.8% 2.6%
Steering & suspension 2.9% 2.3%
Tyres & wheels 1.2% 3.2%
Fuel & exhaust 0.7% 0.4%
Structure & body 0.7% 0.3%
Drive system 0.8% 0%

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 Yamaha RD Suzuki AN400
2016 90.5% 85.5%
2017 89.3% 86.8%
2018 89.2% 85.7%
2019 93.5% 84.4%
2020 93.1% 84.5%
2021 91.5% 85.1%
2022 89.3% 83.0%
2023 97.5% 83.0%

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 Yamaha RD Suzuki AN400
0k-10k miles 85.4% 91.7%
10k-20k miles 85.2% 86.7%
20k-30k miles 87.2% 82.7%
30k-40k miles 84.8% 81.0%
40k-50k miles 88.8% 79.7%

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

Yamaha RD vs Suzuki AN400 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Yamaha RD or the Suzuki AN400?

The Suzuki AN400 passes its MOT first time more often than the Yamaha RD: 86.2% vs 86.0%, a 0.2-point lead. Adjusted for age, mileage and test class the two are level (+2.1 vs +1.3 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 Yamaha RD fail its MOT on most?

Lights & signalling: 3.8% of Yamaha RD MOT tests failed on it, then brakes (3.0%).

What does the Suzuki AN400 fail its MOT on most?

Brakes: 4.4% of Suzuki AN400 MOT tests failed on it, then tyres & wheels (3.2%).

Which holds up better at high mileage, the Yamaha RD or the Suzuki AN400?

At 40k-50k miles the Yamaha RD passes first time more often: 88.8% for the Yamaha RD vs 79.7% for the Suzuki AN400.

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