Listed gear-ratio data for 2003 Mercury 90 HP 3-Cylinder 2-Stroke outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2003 Mercury 90 HP 3-Cylinder 2-Stroke
Listed ratio values: 2.31:1
| Model | Gear ratio |
|---|---|
| 1989-2004 | 2.31:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.