Listed gear-ratio data for 2001 Mariner 90 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2001 Mariner 90 HP
Listed ratio values: 2.07:1, 2.31:1
| Model | Gear ratio |
|---|---|
| 90 TwoStroke - 3 cylinder | 2.31:1 |
| F90 FourStroke - early generation | 2.07:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.