| Cylinders | 1 |
| Bore | 80 mm (RY 85) - 85 mm (RY 100-101) - 87 mm (RY 120-121) |
| Stroke | 76 mm (RY 85-100-101) - 85 mm (RY 120-121) |
| Displacement | 382 cm3 (RY 85) - 431 cm3 (RY 100-101) - 505 cm3 (RY 120-121)) |
| Max inclination during operation | 30°, max 30 min / 35°, max 1 min |
| Oil capacity (MAX level.) including oil filter | 1,3 lt. |
| Dry weight | 45 kg (RY 85) - 46,5 (RY 100-101) - 48 (RY 120-121) |
