Listed gear-ratio data for 1999 Mariner 2.5 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
1999 Mariner 2.5 HP
Listed ratio values: 1.85:1
| Model | Gear ratio |
|---|---|
| 2.5 TwoStroke | 1.85:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.