Diagnose Lower Unit Malfunction
Trouble Check Chart
| Condition | Possible cause | Correction / Reference Item |
|---|---|---|
| Engine stalls when engaging gear | Idling speed set too low | Adjustment |
| Engine stalls when engaging gear | Propeller shaft bearings damaged, lacking lubrication or seized. | Replace |
| Engaging gear(s) has no effect on propulsion | Clutch out of adjustment | Adjustment |
| Engaging gear(s) has no effect on propulsion | Driveshaft broken or splines damaged | Replace |
| Engaging gear(s) has no effect on propulsion | Chipped or worn dog clutches | Replace |
| Engaging gear(s) has no effect on propulsion | Propeller not secured correctly (fallen off). | Inspection or retighten |
| Loss of power (Assuming engine is OK) | Propeller bush slipping. | Replace |
| Loss of power (Assuming engine is OK) | Bent or worn propeller. | Repair or replace |
| Engine shakes the boat | Failed propeller bush. | Replace |
| Engine shakes the boat | Bent driveshaft or propeller shaft | Replace |
| Engine shakes the boat | Damaged propeller. | Replace |
| Clutch will not engage or disengage | Seized shift rod | Inspection |
| Clutch will not engage or disengage | Clutch shaft and clutch rod have become detached | Inspection |
| Clutch will not engage or disengage | Electronic shift control system is failed | Inspection |
