What two-stroke oil does a Tohatsu 40 two-stroke, two-cylinder use?

Genuine engine oil or any NMMA certified TC-W3 2-cycle outboard engine oil. Do not use automotive oils.

What is the fuel to oil ratio for a Tohatsu 40 two-stroke, two-cylinder?

50:1 gasoline/oil mixture (2% oil). New engines or reconditioned powerheads: 25:1 (4% oil) during the 10 hour break-in.

What gear oil does a Tohatsu 40 two-stroke, two-cylinder use, and how much?

Genuine manufacturer gear oil or API GL5, SAE #80 to #90. Quantity: Approx. 14.2 U.S. fl oz (420 mL).

What spark plug does a Tohatsu 40 two-stroke, two-cylinder use?

NGK BR7HS-10 or Champion RL82C10 (with resistor), qty 2. Gap: 0.035 to 0.039 in (0.9 to 1.0 mm).

How often should a Tohatsu 40 two-stroke, two-cylinder be serviced?

The factory schedule lists: Initial 10 hours or 2 days; Every 30 hours or 7 days; Every 50 hours or 30 days; Every 100 hours or 60 days; Every 200 hours or 12 months. 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 Tohatsu 40 two-stroke, two-cylinder?

The factory schedule says to replace it at 200 hours, and we follow that. In any case we never let it go longer than a year in Hawaiʻi's salt water.

What is the idle speed of a Tohatsu 40 two-stroke, two-cylinder?

850 rpm in gear; 1000 rpm in neutral.

What is the propeller nut torque on a Tohatsu 40 two-stroke, two-cylinder?

29.4 to 39.2 N·m (3.0 to 4.0 kg-m, 21.7 to 28.9 ft-lb).

Tohatsu 40 two-stroke, two-cylinder (493 cc) service guide

Oil, gear oil, spark plugs and the service schedule for the Tohatsu 40 two-stroke, two-cylinder (493 cc) (40 hp, two-stroke), from the factory service manual, plus how we service it in Hawaiʻi.

Quick answers

What two-stroke oil does a Tohatsu 40 two-stroke, two-cylinder use?: Genuine engine oil or any NMMA certified TC-W3 2-cycle outboard engine oil. Do not use automotive oils.
What is the fuel to oil ratio for a Tohatsu 40 two-stroke, two-cylinder?: 50:1 gasoline/oil mixture (2% oil). New engines or reconditioned powerheads: 25:1 (4% oil) during the 10 hour break-in.
What gear oil does a Tohatsu 40 two-stroke, two-cylinder use, and how much?: Genuine manufacturer gear oil or API GL5, SAE #80 to #90. Quantity: Approx. 14.2 U.S. fl oz (420 mL).
What spark plug does a Tohatsu 40 two-stroke, two-cylinder use?: NGK BR7HS-10 or Champion RL82C10 (with resistor), qty 2. Gap: 0.035 to 0.039 in (0.9 to 1.0 mm).
How often should a Tohatsu 40 two-stroke, two-cylinder be serviced?: The factory schedule lists: Initial 10 hours or 2 days; Every 30 hours or 7 days; Every 50 hours or 30 days; Every 100 hours or 60 days; Every 200 hours or 12 months. 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 Tohatsu 40 two-stroke, two-cylinder?: The factory schedule says to replace it at 200 hours, and we follow that. In any case we never let it go longer than a year in Hawaiʻi's salt water.
What is the idle speed of a Tohatsu 40 two-stroke, two-cylinder?: 850 rpm in gear; 1000 rpm in neutral.
What is the propeller nut torque on a Tohatsu 40 two-stroke, two-cylinder?: 29.4 to 39.2 N·m (3.0 to 4.0 kg-m, 21.7 to 28.9 ft-lb).

Maintenance specs

Two-stroke oil	Genuine engine oil or any NMMA certified TC-W3 2-cycle outboard engine oil. Do not use automotive oils
Fuel to oil mix	50:1 gasoline/oil mixture (2% oil). New engines or reconditioned powerheads: 25:1 (4% oil) during the 10 hour break-in
Gear oil	Genuine manufacturer gear oil or API GL5, SAE #80 to #90
Gear oil quantity	Approx. 14.2 U.S. fl oz (420 mL)
Gear oil upper and lower oil plugs	2 plugs.
Gearcase pressure and vacuum test	Pressure 3 to 6 psi (20 to 39 kPa, 0.2 to 0.4 kg/cm2) at the oil level plug hole; then vacuum 3 to 5 in (76 to 127 mm) of mercury
Spark plug	NGK BR7HS-10 or Champion RL82C10 (with resistor), qty 2
Spark plug gap	0.035 to 0.039 in (0.9 to 1.0 mm)
Spark plug torque	25 to 29 N·m (2.6 to 3.0 kg-m, 19 to 21 ft-lb)
Idle speed	850 rpm in gear; 1000 rpm in neutral
Thermostat	Opening temperature 125.6 °F (52 °C)
Fuel hoses	Replace the fuel and recirculation hoses every 2 years. The tune-up procedure replaces the fuel filter
Anodes	Replace when the anode has been reduced to 2/3 of its original size (1/3 eroded)
Propeller nut	29.4 to 39.2 N·m (3.0 to 4.0 kg-m, 21.7 to 28.9 ft-lb)

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.

Initial 10 hours or 2 days

Replace: gear case oil, gear case plug gaskets, propeller cotter pin

Check: spark plugs
Every 30 hours or 7 days

Replace: gear case plug gaskets

Check: gear case oil
Every 50 hours or 30 days

Replace: spark plugs, gear case oil, gear case plug gaskets, propeller cotter pin

Check: water pump impeller, anodes
Every 100 hours or 60 days

Replace: spark plugs, gear case oil, gear case plug gaskets, propeller cotter pin

Check: water pump impeller, thermostat, anodes
Every 200 hours or 12 months

Replace: spark plugs, gear case oil, gear case plug gaskets, propeller cotter pin, water pump impeller

Check: thermostat, anodes

Source: Tohatsu 1-/2-Cylinder two-stroke service manual, PNo. 003-21035-1. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.

Tohatsu 40 two-stroke, two-cylinder (493 cc) service guide

Quick answers

Maintenance specs

Service schedule

Initial 10 hours or 2 days

Every 30 hours or 7 days

Every 50 hours or 30 days

Every 100 hours or 60 days

Every 200 hours or 12 months

Other Tohatsu guides