Mesin dan Performa dari Yamaha Mio M3 125 yaitu:
| Varian | Yamaha Mio M3 125 AKS-SSS | Yamaha Mio M3 125 Standard |
| Konfigurasi Katup | SOHC | SOHC |
| Kecepatan maksimum | 100 kmph | 100 kmph |
| Rasio Kompresi | 9.5:1 | 9.5:1 |
| Busi per silinder | 1 | 1 |
| Launch Control | N | N |
| RPM torsi maksimum | 5500 rpm | 5500 rpm |
| Jumlah silinder | 1 | 1 |
| Sistem pelumasan | Wet Sump | Wet Sump |
| RPM Tenaga Maksimum | 8000 rpm | 8000 rpm |
| Konsumsi Bahan Bakar | 47.6 kmpl | 47.6 kmpl |
| Sistem Pendinginan | ||
| Sistem pembakaran | TCI | TCI |
| Katup Per Silinder | 2 | 2 |
| Torsi Maksimal | 9.6 Nm | 9.6 Nm |
| Diameter x langkah | 52.4 mm x 57.9 mm | 52.4 mm x 57.9 mm |
| Jumlah langkah | 4-Stroke | 4-Stroke |
| Jenis Kopling | Dry,Centrifugal, Automatic | Dry,Centrifugal, Automatic |
| Pipa Knalpot | Single Exhaust | Single Exhaust |
| Tipe filter udara | ||
| Kontrol Emisi | Euro 3 | Euro 3 |
