What two-stroke oil does a Tohatsu MD70B / MD90B TLDI use?

Genuine MD Platinum or equivalent.

What gear oil does a Tohatsu MD70B / MD90B TLDI use, and how much?

Genuine gear oil or API GL5, SAE #80 to #90. Quantity: 900 ml (30.4 US fl oz), approx.

What spark plug does a Tohatsu MD70B / MD90B TLDI use?

NGK PZFR6H, qty 3. Gap: 0.7 to 0.8 mm (0.0276 to 0.0315 in).

How often should a Tohatsu MD70B / MD90B TLDI be serviced?

The factory schedule lists: First 10 hours or bimonthly; First 30 hours or monthly; At 50 hours or 3 months; At 100 hours or 6 months; Yearly, done with the 200 hours service or once a year. 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 MD70B / MD90B TLDI?

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 MD70B / MD90B TLDI?

700 / 800 / 900 rpm (3 stages variable), idling and trolling.

Tohatsu MD70B / MD90B TLDI (3 cylinder, 1,267 cc, direct injection two-stroke) service guide

Oil, gear oil, spark plugs and the service schedule for the Tohatsu MD70B / MD90B TLDI (3 cylinder, 1,267 cc, direct injection two-stroke) (70 to 90 hp, two-stroke), from the factory service manual, plus how we service it in Hawaiʻi.

Models covered: TLDI 70B and 90B, EPTO: two-stroke gasoline engine with direct fuel injection, 3 cylinders, 1267 ml (77.3 cu in), bore 86 x stroke 72.7 mm; 70B 51.5 kW (70 PS), 90B 66.2 kW (90 PS); WOT range 5150 to 5850 rpm; gear ratio 2.33 (12:28) on the 70B and 2.0 (13:26) on the 90B; oil injection with a 4 L oil tank; ECU, inductive ignition. The later MD75C2 / MD90C2 have their own sheet.

Quick answers

What two-stroke oil does a Tohatsu MD70B / MD90B TLDI use?: Genuine MD Platinum or equivalent.
What gear oil does a Tohatsu MD70B / MD90B TLDI use, and how much?: Genuine gear oil or API GL5, SAE #80 to #90. Quantity: 900 ml (30.4 US fl oz), approx.
What spark plug does a Tohatsu MD70B / MD90B TLDI use?: NGK PZFR6H, qty 3. Gap: 0.7 to 0.8 mm (0.0276 to 0.0315 in).
How often should a Tohatsu MD70B / MD90B TLDI be serviced?: The factory schedule lists: First 10 hours or bimonthly; First 30 hours or monthly; At 50 hours or 3 months; At 100 hours or 6 months; Yearly, done with the 200 hours service or once a year. 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 MD70B / MD90B TLDI?: 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 MD70B / MD90B TLDI?: 700 / 800 / 900 rpm (3 stages variable), idling and trolling.

Maintenance specs

Injection (two-stroke) oil	Genuine MD Platinum or equivalent
Oil tank	4 L (4.2 US qt); electric oil pump
Gear oil	Genuine gear oil or API GL5, SAE #80 to #90
Gear oil quantity	900 ml (30.4 US fl oz), approx.
Gear oil drain and level plugs (lower and upper oil plug)	Remove the lower oil plug and gasket, then the upper oil plug and gasket; fill through the lower hole until oil overflows from the upper hole; tighten the upper plug first. Replace both gaskets with new ones
Spark plug	NGK PZFR6H, qty 3
Spark plug gap	0.7 to 0.8 mm (0.0276 to 0.0315 in)
Spark plug torque	25 to 29 N·m (2.5 to 3.0 kg-m), 18 to 22 ft-lb
Idle / trolling speed	700 / 800 / 900 rpm (3 stages variable), idling and trolling
Thermostat	With wax-type pressure relief valve: valve start temperature 60 °C (140 °F), full-open 75 °C (167 °F) or higher, full open lift 3 mm (0.12 in) or more
Power trim and tilt fluid	Power Torque fluid (ATF Dexron III or equivalent product), 682 ml (23.04 fl oz)
Air compressor drive belt	Check tension and appearance. Driven pulley nut 44 to 49 N·m (32 to 36 ft-lb); drive pulley nut 90 to 110 N·m (65 to 80 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.

First 10 hours or bimonthly

Replace: gear case oil, gear case plug gaskets, propeller cotter pin
First 30 hours or monthly

Replace: gear case plug gaskets, propeller cotter pin

Check: spark plugs
At 50 hours or 3 months

Replace: gear case plug gaskets, propeller cotter pin

Check: fuel filter, gear case oil, water pump impeller, anodes
At 100 hours or 6 months

Replace: gear case plug gaskets, propeller cotter pin

Check: spark plugs, fuel filter, gear case oil, water pump impeller, anodes
Yearly, done with the 200 hours service or once a year

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

Check: spark plugs, gear case oil, anodes

Source: Tohatsu TLDI 70B/90B service manual, OB No. 003-21052-1. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.

Tohatsu MD70B / MD90B TLDI (3 cylinder, 1,267 cc, direct injection two-stroke) service guide

Quick answers

Maintenance specs

Service schedule

First 10 hours or bimonthly

First 30 hours or monthly

At 50 hours or 3 months

At 100 hours or 6 months

Yearly, done with the 200 hours service or once a year

Other Tohatsu guides