Listed gear-ratio data for 2003 Mariner 100 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2003 Mariner 100 HP
Listed ratio values: 2.07:1, 2.31:1
| Model | Gear ratio |
|---|---|
| 100 TwoStroke - 4 cylinder | 2.07:1, 2.31:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.