Data as of: DVSA MOT results to 2025
Gas Gas Ec 300 vs Yamaha RD350
The Yamaha RD350 passes its MOT first time more often than the Gas Gas Ec 300: 86.3% vs 78.8%, a 7.5-point lead.
MOT reliability, side by side
| Metric | Gas Gas Ec 300 | Yamaha RD350 |
|---|---|---|
| First-time pass rate | 78.8% | 86.3% |
| Outright fail rate | 12.2% | 6.6% |
| Vs comparable bikes (age & mileage adjusted) | -10.3 pts | +2.4 pts |
| Engine size | 299cc | 347cc |
| Rank among all models | #3805 of 5428 | #2120 of 5428 |
| Median miles at test | 1,372 | 23,256 |
| MOT tests analysed | 2,832 | 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.
What fails, side by side
| Component | Gas Gas Ec 300 | Yamaha RD350 |
|---|---|---|
| Lights & signalling | 6.7% | 3.2% |
| Steering & suspension | 6.0% | 2.5% |
| Brakes | 2.5% | 2.7% |
| Tyres & wheels | 3.6% | 0.9% |
| Drive system | 0.9% | 0.5% |
| Structure & body | 0.6% | 0.4% |
| Fuel & exhaust | 0.5% | 0.4% |
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
| Test year | Gas Gas Ec 300 | Yamaha RD350 |
|---|---|---|
| 2018 | 71.8% | 88.8% |
| 2019 | 79.0% | 91.0% |
| 2020 | 78.1% | 92.0% |
| 2021 | 81.0% | 90.1% |
| 2022 | 83.3% | 90.5% |
| 2023 | 83.3% | 92.2% |
| 2024 | 84.7% | 94.8% |
| 2025 | 82.1% | 93.5% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Gas Gas Ec 300 vs Yamaha RD350 FAQ
Which is more reliable, the Gas Gas Ec 300 or the Yamaha RD350?
The Yamaha RD350 passes its MOT first time more often than the Gas Gas Ec 300: 86.3% vs 78.8%, a 7.5-point lead. Adjusted for age, mileage and test class, the Yamaha RD350 still comes out ahead: -10.3 points vs comparable bikes for the Gas Gas Ec 300, +2.4 for the Yamaha RD350. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Gas Gas Ec 300 fail its MOT on most?
Lights & signalling: 6.7% of Gas Gas Ec 300 MOT tests failed on it, then steering & suspension (6.0%).
What does the Yamaha RD350 fail its MOT on most?
Lights & signalling: 3.2% of Yamaha RD350 MOT tests failed on it, then brakes (2.7%).
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.