Mercury 40 / 50 / 60 EFI FourStroke (4 cylinder, 995 cc) service guide

Quick answers

How much oil does a Mercury 40 / 50 / 60 EFI FourStroke take?

3.0 L (3.0 US qt) with filter.

What engine oil does a Mercury 40 / 50 / 60 EFI FourStroke use?

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

What gear oil does a Mercury 40 / 50 / 60 EFI FourStroke use, and how much?

High Performance or Premium Gear Lubricant; the filling procedure says High Performance only. Quantity: Standard 1.83:1 about 340 ml (11.5 fl oz); Command Thrust 2.33:1 about 710 ml (24 fl oz).

What spark plug does a Mercury 40 / 50 / 60 EFI FourStroke use?

Champion RA8HC, 16 mm hex, qty 4. Gap: 1.0 mm (0.040 in).

How often should a Mercury 40 / 50 / 60 EFI FourStroke be serviced?

The factory schedule lists: Annually or 100 hours; Three years or 300 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 40 / 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 40 / 50 / 60 EFI FourStroke?

In gear 725 ± 25 r/min; warm idle 750 ± 25 r/min.

What is the propeller nut torque on a Mercury 40 / 50 / 60 EFI FourStroke?

75 N·m (55.3 lb·ft); bend the retainer tabs.

Maintenance specs

Engine oil	NMMA FC-W synthetic blend SAE 25W-40 all temperatures; FC-W 10W-30 below 4 °C (40 °F)
Engine oil quantity	3.0 L (3.0 US qt) with filter
Oil drain plug (driveshaft housing)	24 N·m (17.7 lb·ft)
Gear lubricant	High Performance or Premium Gear Lubricant; the filling procedure says High Performance only
Gearcase capacity	Standard 1.83:1 about 340 ml (11.5 fl oz); Command Thrust 2.33:1 about 710 ml (24 fl oz)
Gearcase plugs	Standard: drain plug 6.5 N·m (58 lb·in), vent screw 6.8 N·m (60 lb·in). Command Thrust: drain screws 7 N·m (62 lb·in), vent screw 6.8 N·m (60 lb·in)
Gearcase leak test	69 to 83 kPa (10 to 12 psi); 5 minutes, 15 minutes
Spark plug	Champion RA8HC, 16 mm hex, qty 4
Spark plug gap	1.0 mm (0.040 in)
Spark plug torque	17 N·m (150 lb·in), or finger tight then 1/4 turn
Idle speed	In gear 725 ± 25 r/min; warm idle 750 ± 25 r/min
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). Command Thrust: 800 r/min 14 to 41 kPa (2 to 6 psi), 6000 r/min 83 to 172 kPa
Anodes	Trim tab screw 30 N·m (22 lb·ft); gearcase side anodes 7 N·m (62 lb·in); transom bracket anode M6 x 25 bolts 6.8 N·m (60 lb·in), 6 N·m (53 lb·in)
Propeller nut	75 N·m (55.3 lb·ft); bend the retainer tabs
Power trim fluid	Power Trim and Steering Fluid or ATF Dexron III, to the bottom of the fill hole
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); locknut 13.5 N·m (120 lb·in)
Timing belt	Replace if cracked, worn, oily, or it deflects 10 mm (0.39 in) or more; accessory drive belt (if equipped) replaced at 3 years / 300 h

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. Annually or 100 hours

   Replace: engine oil, oil filter, oil drain plug gasket, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin

   Check: 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, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller

   Check: thermostat, anodes

3. Three years or 300 hours

   Replace: engine oil, oil filter, oil drain plug gasket, spark plugs, fuel filter, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller

   Check: 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 40/50/60, 40/50/60 SeaPro, 40 Jet FourStroke EFI service manual, 90-8M0105570. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.