Listed gear-ratio data for 2005 Mercury 25 HP Marathon outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2005 Mercury 25 HP Marathon
Listed ratio values: 2.25:1
| Model | Gear ratio |
|---|---|
| 0G760300-0T979999 | 2.25:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.