Listed gear-ratio data for 1997 Mariner 9.9 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
1997 Mariner 9.9 HP
Listed ratio values: 2.00:1, 2.01:1
| Model | Gear ratio |
|---|---|
| 9.9 TwoStroke | 2.00:1 |
| F9.9 FourStroke - early generation | 2.01:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.