Beta Alp 4.0 vs Yamaha RD350

The Yamaha RD350 passes its MOT first time more often than the Beta Alp 4.0: 86.3% vs 80.1%, a 6.2-point lead.

MOT reliability, side by side

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

Metric	Beta Alp 4.0	Yamaha RD350
First-time pass rate	80.1%	86.3%
Outright fail rate	6.5%	6.6%
Vs comparable bikes (age & mileage adjusted)	-7.4 pts	+2.4 pts
Engine size	350cc	347cc
Rank among all models	#3557 of 5428	#2120 of 5428
Median miles at test	6,550	23,256
MOT tests analysed	336	19,574
Most common failure	lighting and signalling	lighting and signalling

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 mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Beta Alp 4.0	Yamaha RD350
0k-10k miles	78.3%	88.9%
10k-20k miles	82.2%	87.5%

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

BETA ALP 4.0 80.1% pass · 336 tests YAMAHA RD350 86.3% pass · 19.6k tests

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