Mercury 50 / 60 EFI FourStroke (4 cylinder, 2005 to 2008) service guide

Quick answers

How much oil does a Mercury 50 / 60 EFI FourStroke take?

3.0 L (3 US qt) with filter.

What engine oil does a Mercury 50 / 60 EFI FourStroke use?

FC-W synthetic blend 25W-40; FC-W 10W-30 below 4 °C (40 °F).

What gear oil does a Mercury 50 / 60 EFI FourStroke use, and how much?

Premium Gear Lubricant. Quantity: Standard 1.83:1 about 340 ml (11.5 fl oz); BigFoot 2.31:1 and 2.33:1 about 710 ml (24 fl oz).

What spark plug does a Mercury 50 / 60 EFI FourStroke use?

Champion RA8HC. Gap: 1.0 mm (0.040 in).

How often should a Mercury 50 / 60 EFI FourStroke be serviced?

The factory schedule lists: Every 100 hours or once a year; Every 300 hours or 3 years; Every 400 hours. In Hawaiʻi's salt water we do a full yearly service every 200 hours or 1 year, whichever comes first, and a new engine needs its first (break-in) service.

When should the water pump impeller be replaced on a Mercury 50 / 60 EFI FourStroke?

The factory schedule says to replace it at 300 hours. In Hawaiʻi's warm salt water we replace it every 200 hours or 1 year, whichever comes first, because a worn impeller is the most common cause of overheating.

What is the idle speed of a Mercury 50 / 60 EFI FourStroke?

725 ± 25 r/min, set by the ECM, not adjustable.

What is the propeller nut torque on a Mercury 50 / 60 EFI FourStroke?

75 N·m (55 lb·ft); bend the retainer tabs.

Maintenance specs

Engine oil	FC-W synthetic blend 25W-40; FC-W 10W-30 below 4 °C (40 °F)
Engine oil quantity	3.0 L (3 US qt) with filter
Oil filter	3/4 to 1 turn after the gasket touches
Oil drain plug	24 N·m (17.5 lb·ft)
Gear lubricant	Premium Gear Lubricant
Gearcase capacity	Standard 1.83:1 about 340 ml (11.5 fl oz); BigFoot 2.31:1 and 2.33:1 about 710 ml (24 fl oz)
Gearcase drain plugs and vent screw	Standard: drain plugs 6.5 N·m (58 lb·in), vent screw 6.7 N·m (60 lb·in). BigFoot: vent screw 6.7 N·m (60 lb·in)
Gearcase leak test	69 to 83 kPa (10 to 12 psi) for 5 minutes
Spark plug	Champion RA8HC
Spark plug gap	1.0 mm (0.040 in)
Idle speed	725 ± 25 r/min, set by the ECM, not adjustable
Thermostat	Starts to open 48 to 51 °C (118 to 123 °F); lift at least 3 mm (0.12 in) above 63 °C (145 °F)
Water pressure	Standard: 800 r/min 7 to 21 kPa (1 to 3 psi), 6000 r/min 83 to 172 kPa (12 to 25 psi). BigFoot: 800 r/min 14 to 41 kPa (2 to 6 psi)
Transom bracket anode bolts (M6 x 25)	6 N·m (54 lb·in)
Propeller nut	75 N·m (55 lb·ft); bend the retainer tabs
Valve clearance, cold	IN 0.15 to 0.25 mm (0.006 to 0.010 in); EX 0.25 to 0.35 mm (0.010 to 0.014 in)

Service schedule

The factory maintenance intervals, with what is replaced and what is checked at each. Rows marked Hawaiʻi are our shop's yearly service for salt water use.

1. Every 100 hours or once a year

   Replace: engine oil, oil filter, oil drain plug gasket, spark plugs, gear case oil, gear case plug gaskets

   Check: fuel filter, thermostat, anodes

2. Every 200 hours or 1 year (our Hawai‘i yearly service) Hawai‘i

   Replace: engine oil, oil filter, oil drain plug gasket, gear case oil, gear case plug gaskets, water pump impeller

   Check: spark plugs, fuel filter, thermostat, anodes

3. Every 300 hours or 3 years

   Replace: engine oil, oil filter, oil drain plug gasket, gear case oil, gear case plug gaskets, water pump impeller

   Check: spark plugs, fuel filter, thermostat, anodes

4. Every 400 hours

   Replace: engine oil, oil filter, oil drain plug gasket, gear case oil, gear case plug gaskets, water pump impeller

   Check: spark plugs, fuel filter, thermostat, anodes

We replace the water pump impeller at every service from 200 hours up, which can be sooner than the factory schedule, because of Hawaiʻi’s warm salt water.

Source: Mercury 50/60 FourStroke, 40/50/60 BigFoot FourStroke EFI 4 Cyl. service manual, 90-883065R02. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.