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Tohatsu M40D2 Specifications
| Engine Model: Tohatsu M40D2 |
| Engine Type: 2-stroke 3-cylinder gasoline outboard engine |
| Total Displacement: 42.5 cu.in (697 cc) |
| Rated Engine Power: 40 Hp (29.4 kW) at 5500 rpm |
| Fuel System: Carburetor |
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| General Technical Data |
The Tohatsu M40D2 is a three-cylinder,
loop-charged two-stroke outboard delivering 40 horsepower. Offered in
multiple configurations - including manual start with tiller handle
(MF), electric start with tiller (EFTO), remote electric start with
manual tilt (EPO), and remote electric start with power trim and tilt
(EPTO) - this engine balances proven technology with user-friendly
features.
The Tohatsu M40D2 represents a well-engineered and dependable outboard
option. Its in-line three-cylinder design provides smooth operation with
good fuel economy, thanks to loop-charged induction. Users appreciate
the engine's straightforward design, which contributes to its reputation
for reliability. A key strength across multiple models is the
availability of features like an 11-amp alternator for powering
electronics and an optional power trim and tilt system. The engine is
built with corrosion-resistant materials, including high-grade marine
aluminum alloy and zinc-coated internal water passages, enhancing its
longevity, especially in saltwater environments.
Engine Model: Tohatsu M40D2 MF, EFTO, EPO, EPTO
Engine Type: 2-Stroke.
Number of Cylinders: 3.
Bore x Stroke: 68 mm x 64 mm (2.68 in x 2.52 in).
Piston Displacement: 697 cc (42.53 cu in).
Power Output: 29.4 kW (40 HP).
Full Throttle Operating Range: 5000-5700 r/min.
Idle Speed in Neutral Gear: 900 r/min.
Minimum Trolling Speed in Forward Gear: 750 r/min.
Exhaust System: Through-hub exhaust.
Cooling System: Water cooling with thermostat control.
Starting System: Manual (MF model) / Electric starter motor (EFTO, EPO,
EPTO models).
Ignition System: Flywheel Magneto CDI (Capacitor Discharge Ignition).
Spark Plug: NGK B7HS-10 or BR7HS-10 (for 40D2).
Spark Plug Gap: 0.9-1.0 mm (0.035-0.039 in).
Alternator: 12V, 130W, 11A (Standard on electric start models).
Trim System: Manual trim and tilt (MF, EPO models) / Power trim and tilt
(EFTO, EPTO models).
Steering Angle (MF, EPO): 80 degrees.
Steering Angle (EFTO, EPTO): 70 degrees.
Trim Angle (MF, EPO): -8 to 12 degrees.
Trim Angle (EFTO, EPTO): -4 to 14 degrees.
Trim Position (MF, EPO): 6.
Trim Position (EFTO, EPTO): 4.
Tilt Up Angle (MF, EPO): 63 degrees.
Tilt Up Angle (EFTO, EPTO): 62 degrees.
Gear Shift: Dog clutch (F-N-R).
Gear Reduction Ratio: 1.85 (24:13 or 13:24).
Fuel: Unleaded Regular Gasoline with an anti-knock index (R+M/2) of 87
or higher, or a Research Octane Number (RON) of 91 or higher.
Fuel Tank Capacity: 25 L (6.6 US gal) Separate fuel tank.
Engine Oil: Genuine two-stroke engine oil or NMMA certified TC-W3
outboard oil.
Engine Oil Mixing Ratio: 50:1 (Pre-mix for manual start models) /
Auto-mixing for specific electric start models. Gear Oil: API GL-5, SAE
80-90.
Gear Oil Capacity: 0.5 L (16.9 US fl oz / 17.6 Imp fl oz).
PTT Fluid (EFTO, EPTO): ATF (Automatic Transmission Fluid) Dexron III.
| Powerhead |
The M40D2 features a loop-charged, three-cylinder powerhead. Loop charging is a highly efficient scavenging method that directs the fuel-air mixture in a loop to push out exhaust gases, resulting in smoother operation and improved fuel economy compared to older cross-flow designs.
The engine is built with a high-grade marine aluminum alloy for the block and other components, providing excellent corrosion resistance and durability while keeping weight low. The CD ignition system contributes to quick and reliable starts.
| Fuel System |
The fuel system is carbureted. It is designed to run on standard 87-octane unleaded gasoline. A separate 25-liter fuel tank is provided with the outboard. For cold starts, the engine is equipped with a choke knob for manual enrichment.
| Lubrication System |
0The lubrication system varies by model. The base manual start (MF) model requires fuel pre-mixed at a 50:1 ratio. Many electric start versions, such as the EPOS and EPTOL, feature Tohatsu's automixing oil injection system for optimum lubrication under varying loads, which simplifies refueling. For these automixing models, a 2-liter engine oil tank is located conveniently on top of the motor for easy refills.
| Cooling System |
Cooling is managed by a forced water system that is thermostatically controlled to maintain a consistent engine temperature for optimal performance and longevity. The system features a water pump with a durable stainless steel housing for outstanding reliability.
An overheat warning (audible alarm) alerts the operator if the engine approaches a critical temperature. A water pressure sensor is also incorporated into the system.
| Mid Section and Lower Unit |
The M40D2 is fitted with a durable mid section and lower unit housing a forward-neutral-reverse dog clutch. The gear reduction ratio is 1.85:1 (24:13). The recommended gear oil is an API GL-5, SAE 80-90 grade, with a total capacity of 0.5 liters.
The lower unit is equipped with a replaceable trim tab, which also serves as a sacrificial anode for corrosion protection. The through-hub exhaust system contributes to quieter operation.
| Trim and Tilt System |
The M40D2 is offered with two types of trim systems. The MF and EPO models feature a manual trim and tilt system with six trim positions and a tilt angle of up to 63 degrees. This system includes a reverse lock lever and a thrust rod for shallow water drive.
The EFTO and EPTO models are equipped with a power trim and tilt system, which uses electric hydraulic pumps to adjust the motor's angle. This system uses Dexron III Automatic Transmission Fluid and has a manual relief valve for emergency operation.
| Propeller Information |
The recommended propeller selection range for the M40D2 is from 7 to 15 inches of pitch. The correct propeller must be selected so that the engine operates within its wide-open throttle (WOT) range of 5000-5700 r/min under a normal load for optimal performance and engine longevity.
| Dimensions and Weight |
Overall Length (MF, EFTO): 1143 mm (45.0 in)
Overall Length (EPO, EPTO): 630 mm (24.8 in)
Overall Width (MF, EFTO): 384 mm (15.1 in)
Overall Width (EPO, EPTO): 345 mm (13.6 in)
Overall Height (Short Shaft MF/EFTO): 1225 mm (48.2 in)
Overall Height (Short Shaft EPO/EPTO): 1192 mm (46.9 in)
Overall Height (Long Shaft MF/EFTO): 1352 mm (53.2 in)
Overall Height (Long Shaft EPO/EPTO): 1319 mm (51.9 in)
Transom Height (Short Shaft): 403 mm (15.9 in)
Transom Height (Long Shaft): 530 mm (20.9 in)
Weight (Short Shaft MF): 72 kg (159 lb)
Weight (Short Shaft EFTO): 87.5 kg (193 lb)
Weight (Short Shaft EPO): 74.5 kg (164 lb)
Weight (Short Shaft EPTO): 83.5 kg (184 lb)
Weight (Long Shaft MF): 73.5 kg (162 lb)
Weight (Long Shaft EFTO): 89 kg (196 lb)
Weight (Long Shaft EPO): 76 kg (168 lb)
Weight (Long Shaft EPTO): 85 kg (187 lb)
| Maintenance Data |
First 20 Hours / 1 Month: Initial dealer inspection. Every 50 Hours / 3
Months: Check and clean the fuel filter. Inspect spark plugs, clean or
replace as needed, and adjust gap to 0.9-1.0 mm (0.035-0.039 in). Check
and re-tighten all accessible bolts and nuts. Apply grease to all
sliding and rotating parts and grease nipples.
Every 100 Hours / 6 Months: Change gear oil, inspecting for water or
metal particles. Have a dealer check carburetor adjustment and ignition
timing. Inspect the water pump impeller for wear. Annually / Every 100
Hours: Replace the water pump impeller regardless of apparent condition.
General: Check anodes for corrosion and replace if significantly eroded.
Flush the cooling system with fresh water after each use in salt or
polluted water using the flushing attachment.
| Tightening Torques |
Gear Oil Plug: 4 Nm (3 lb-ft)
Propeller Nut: 35 Nm (25 lb-ft, 3.25 kgf·m)
Spark Plug: 27 Nm (20 lb-ft)
PTT Manual Relief Valve: 1.8 Nm (1.4 lb-ft)
| Boat Applications |
The Tohatsu M40D2 is designed for a wide variety of small boats, where its power-to-weight ratio and multiple configurations are advantageous. Ideal applications include: Fishing Boats: A popular choice for small aluminum tiller-steered boats, jon boats, and lightweight center consoles.
Runabouts: Provides strong performance for small fiberglass runabouts and bowriders. Utility Boats: Well-suited for skiffs, inflatables, and other light commercial or recreational utility craft used in sheltered waters. Auxiliary Power: Can serve as reliable auxiliary power for larger sailing yachts.
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