Mash XY 400-2 vs Suzuki GS500

The Mash XY 400-2 passes its MOT first time more often than the Suzuki GS500: 79.8% vs 76.4%, a 3.4-point lead.

MOT reliability, side by side

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

Metric	Mash XY 400-2	Suzuki GS500
First-time pass rate	79.8%	76.4%
Outright fail rate	7.2%	15.0%
Vs comparable bikes (age & mileage adjusted)	-10.3 pts	-7.1 pts
Engine size	397cc	487cc
Rank among all models	#3628 of 5428	#4137 of 5428
Median miles at test	2,907	21,676
MOT tests analysed	208	44,924
Most common failure	lamps and reflectors	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.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested

Test year	Mash XY 400-2	Suzuki GS500
2021	69.2%	78.9%
2022	81.4%	80.6%
2023	80.0%	78.2%
2024	82.1%	79.7%
2025	90.6%	81.5%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

MASH XY 400-2 79.8% pass · 208 tests SUZUKI GS500 76.4% pass · 44.9k tests

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