1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 12Get this manual
Checking Engine Oil IMPORTANT: Do not overfillBe sure that the outboard is upright (not tilted) when checking oil
Oil Changing Procedure
Pump Method 1Place the outboard in an vertical upright position2Remove dipstick and thread Quicksilver Crankcase Oil Pump onto the dipstick tubePump out the engine oil into an appropriate container
1Turn the engine offHave the outboard in level operating positionRemove the top cowl2Flip the handle up and pull out the dipstick (a)Wipe it with clean rag or towel and push it back in all-the-way3Pull the dipstick back out again and observe the oil levelIf the oil level is low, remove the oil filler cap (b) and fill to (but not over) the upper oil level with the recommended oil4Push the dipstick back in all the way; then flip the handle down to lock the dipstick in placeReinstall the oil filler cap and hand tighten securely