Listed gear-ratio data for 2004 Yamaha 90 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2004 Yamaha 90 HP
Listed ratio values: 2.00:1, 2.31:1
| Model | Gear ratio |
|---|---|
| 90TLRC | 2.00:1 |
| F90TLRC | 2.31:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.