Listed gear-ratio data for 1999 Force 90 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
1999 Force 90 HP
Listed ratio values: 1.93:1, 2.00:1
| Model | Gear ratio |
|---|---|
| Force 90 2-Stroke | 2.00:1, 1.93:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.