2003 ST 4 Stroke 9.9/15HP Johnson outboards Service Manual, Page 25Get this manual
PERIODIC MAINTENANCE PERIODIC MAINTENANCE SCHEDULE
PERIODIC MAINTENANCE SCHEDULE
The chart below lists the recommended intervals for all the required periodic service work necessary to keep the motor operating at peak performance and economyMaintenance intervals should be judged by number of hours or months, whichever comes firstNOTE: More frequent servicing should be performed on outboard motors that are used under severe conditions
INTERVAL
INITIAL 10 HRSOR MONTH
EVERY 50 HRSOR MONTHS
EVERY 100 HRSOR MONTHS WITH SAE 10-40
ITEM TO BE SERVICED
SPARK PLUG BREATHER HOSEFUEL LINE ENGINE OIL GEAR OIL LUBRICATION ANODESBONDING WIRES BATTERY BOLTSNUTS ENGINE OIL FILTER FUEL FILTER VALVE CLEARANCE TIMING BELT CARBURETOR PROPELLER NUTPIN WATER PUMP WATER PUMP IMPELLER IDLE SPEED IGNITION TIMING