Listed gear-ratio data for 1999 Yamaha 9.9 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
1999 Yamaha 9.9 HP
Listed ratio values: 2.08:1, 2.92:1
| Model | Gear ratio |
|---|---|
| 9.9MLHX | 2.08:1 |
| 9.9MSHX | 2.08:1 |
| F9.9ELRX | 2.08:1 |
| F9.9MLHX | 2.08:1 |
| F9.9MSHX | 2.08:1 |
| T9.9ELHX | 2.92:1 |
| T9.9ELRX | 2.92:1 |
| T9.9EXHX | 2.92:1 |
| T9.9EXRX | 2.92:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.