Maintenance Schedule
A practical service routine for the MerCruiser MPI engine and Bravo drive. Intervals below follow MerCruiser's general guidance — run whichever comes first, time or hours. Always defer to the MerCruiser Maintenance Guide and the full service manuals for the procedures and torque specs.
The single most important habit: after every outing in
salt or brackish water, flush the engine and drive with fresh water. It does
more for longevity than any other item on this list.
Service Intervals
| Interval | Task |
|---|---|
| Every Use | |
| Before start | Check oil level, bilge, blower before starting (gas fumes) |
| After use (salt) | Flush engine & drive with fresh water |
| After use | Check for fuel/oil/water leaks; wipe down |
| Every 25 Hours | |
| 25 h | Inspect drive gear-lube reservoir level and color |
| 25 h | Inspect anodes; clean/replace as needed |
| Annually / Every 100 Hours | |
| 100 h / yr | Change engine oil & filter |
| 100 h / yr | Change drive gear lube |
| 100 h / yr | Replace fuel filter / water-separating filter |
| 100 h / yr | Inspect/replace spark plugs; check ignition |
| 100 h / yr | Lubricate drive, gimbal, steering, and shift/throttle linkages |
| 100 h / yr | Inspect belts, hoses, clamps, and bellows |
| Annually | Replace anodes; inspect drive for corrosion |
| Every 300 Hours / 3 Years | |
| 300 h / 3 yr | Replace sterndrive water-pump impeller |
| 300 h / 3 yr | Replace U-joint / transom bellows & gimbal bearing as needed |
| Every 2–3 yr | Inspect/replace fuel lines and cool-fuel components |
| Seasonal | |
| Winterize | Drain raw-water side or run antifreeze (closed cooling); fog engine; stabilize fuel |
| Spring | De-winterize; inspect anodes, belts, impeller; test bilge pump & blower |
Fluids & Capacities
Exact grades and capacities depend on your engine displacement and cooling type — confirm against the maintenance guide. Typical references:
| System | Typical Fluid | Notes |
|---|---|---|
| Engine oil | Marine 25W-40 (e.g. MerCruiser 4-cycle) | ~4–5 qt w/ filter; verify by dipstick |
| Sterndrive gear lube | High-performance gear lube (Bravo) | Fill via reservoir; watch for milky color |
| Power steering | Power trim & steering fluid / ATF per spec | Check hydraulic system reservoir |
| Power trim | Power trim & steering fluid | Check trim pump reservoir |
| Coolant (closed cooling only) | Extended-life marine antifreeze | Only if equipped with heat exchanger |
| Fuel | Gasoline per engine spec | Use a water-separating filter; stabilize for storage |
Fill in your own confirmed grades, part numbers, and capacities here as you
service the boat — that turns this into a record specific to your hull.