Tohatsu 40 hp four-stroke outboard motor: full guide for water motor

Japanese brand Tohatsu It has long established itself as a manufacturer of reliable outboard motors that combine advanced technology and affordable price. MFS40A The 40 hp engine is the best choice for 4-5-meter boats, and has become popular with fishermen and water enthusiasts for its efficiency, quiet operation and ease of maintenance.

Four-stroke engines. Tohatsu They stand out against the two-stroke competitors with reduced fuel consumption and minimal emissions of harmful substances, which is especially important for environmentally sensitive water bodies. MFS40A It maintains high acceleration dynamics and resistance to loads, which are key parameters for wave maneuverability, and in this article we will analyze the technical nuances, compare with analogues and give practical recommendations for operation.

Feature of the model - adaptive fuel injection system EFIIt's an automatic mix adjustment based on load and temperature, and it not only makes it easier to start in cold weather, but it also extends the life of the engine. Tohatsu 40 hp confidently pulls a boat with 3-4 passengers even at full load, without losing traction at low revs.

Technical specifications of the Tohatsu MFS40A

Engine. Tohatsu MFS40A It is middle class in power, but technically not inferior to the flagship models. The working volume of 996 cm3 provides stable traction over a wide range of revolutions, and the system OHC (top camshaft) reduces friction and increases efficiency.

• 🔧 Type of enginefour-stroke, 3-cylinder, SOHC
• ⚡ Max. Power.: 40 hp at 5,500 rpm
• ⛽ Fuel consumption: ~10 l/h at cruising speed
• ⚙️ Transmission: 2.33:1 gearbox, mechanical reverse
• 📏 Weight.: 108 kg (with 20 inches of lower unit)
• 🔋 Ignition system: electronic CDI hall-sensor

The cooling system deserves special attention. Thermostatic ControlIt's a system that maintains the optimum engine temperature regardless of external conditions, which is especially important for hot climates or for long periods of low-speed operation (such as trolling), and it has a built-in 12-liter fuel tank, but can also connect to an external tank, which is convenient for long trips.

The additional plus is low noise level (total). 68 dB idlingIt's 10 to 15 percent quieter than two-stroke engines, which is critical for fishermen who value quiet water travel.

Advantages of a four-stroke engine over a two-stroke

The choice between four-stroke and two-stroke engines often comes down to a trade-off between economy and simplicity of design. Tohatsu MFS40A It demonstrates that modern four-stroke engines lack most of the traditional drawbacks.

• 💰 Economy: fuel consumption is 25 to 30 percent lower due to the complete combustion of the mixture in the cylinders. 50,000 rubles/season on gas.
• 🌿 Environmental friendliness: complies with the standard EPA 2020 and EU RCDThis allows the motor to be used on protected water bodies.
• 🔇 Quiet work.There is no characteristic "two-stroke roar", which is important for comfort and camouflage when fishing.
• 🛠️ Resource: With proper maintenance, the motor can withstand to 3,000 motor-hours without major repairs (against 1,500–2,000 for two-stroke).

A critical argument for many is and No need to mix oil with gasolineIn four-stroke engines, the lubricant circulates separately, which makes it easier to refuel and reduces the risk of errors in the preparation of the fuel mixture. Tohatsu MFS40A system-equipped Oil Alert, which automatically silences the engine when the oil level drops - this saves from expensive breakdowns.

⚠️ Attention.When switching from a two-stroke engine to a four-stroke, note that the latter is heavier by 15-20 kg. Check the load capacity of the transom of your boat - for MFS40A minimum strength required Class C (standardized) ISO 10087).

Comparison with analogues: Honda BF50, Mercury 40 ELPT, Yamaha F40

In the market of outboard motors with a capacity of 40 hp Tohatsu MFS40A It competes with models from Honda, Mercury and YamahaTo understand what the Japanese brand offers, compare the key parameters:

Honda BF50 It is considered a standard of reliability, but it loses. Tohatsu price (20-25% more expensive) and weight (115 kg vs. 108 kg). Honda has the advantage of a system BLAST for quick acceleration. Mercury 40 ELPT It is distinguished by the simplicity of design and cheapness of spare parts, but inferior in economy - fuel consumption is higher by 10-15%.

Yamaha F40 closest in character to Tohatsu MFS40Abut has a more complex injection system EFIIt makes it difficult to repair yourself. Yamaha offer up an option Power Tilt (Electrical lift) as standard, and here's a summary table for clarity:

Main advantage Tohatsu MFS40A — Balance of price and technical specificationsIt's cheaper. Honda and YamahaBut they are not as reliable as they are, but they are as efficient as they are. MercuryIf you need a motor to run regularly without the bells and whistles, Tohatsu It's the best choice.

break-in and first maintenance

The right break-in is the key to the long service of the engine. Tohatsu MFS40A The manufacturer recommends the following algorithm:

1. The first 2 hours of idling (no more than 2500 rpm).
2. The next 8 hours - a smooth increase in revolutions to 3,500 rpm.
3. After 10 hours, change the oil and filter (even if the engine is new).

During this period it is strictly forbidden:

• ❌ Give full gas (more than 5000 rpm).
• ❌ Operate the engine with full load (maximum 2-3 people).
• ❌ Long-term work at constant speeds (for example, when trolling).

After the scoring, you need to carry out first-towhich includes:

Oil replacement (SAE 10W-30, 3.3 L) |

Testing and refueling of gearbox oil (GL-5, 220 ml)|

Cleaning of spark plugs (gap 0.9 mm)|

Tightening check of the belt GTM|

Control of the level of antifreeze in the cooling system

⚠️ Attention.: If you find metal shavings in the oil after running, this is normal for new engines. But if there are a lot of shavings (more than 5-7 particles per probe), contact the service - you may need to adjust the valves.

Pay special attention gear-oilIn. Tohatsu MFS40A specialty lubricant Tohatsu Gear Oil (or analogue) Yamalube Gear OilReplacement is required every 100 hours or once a season, and neglecting this procedure causes accelerated wear on gears, which will cost you a lot to replace. 15,000-20,000 rubles..

Typical malfunctions and methods of elimination

Despite the reliability, Tohatsu MFS40A It has a number of weaknesses that you should know about beforehand. misuse Or late T. T. Let's look at the most common cases:

1. The engine does not start or stops on singles

• 🔋 Reason.: Battery discharged or terminals oxidized.
• 🛢️ Reason.: The fuel filter or hose is clogged.
• 🔥 Reason.: The spark plugs failed (check the gap and presence of the charcoal).

DecisionCheck the battery voltage (should be at least) 12.4 In), clean the filter and replace the candles (original - NGK BPR6ES).

Engine overheating

• 🌡️ Reason.: The water intake or thermostat is clogged.
• 💦 Reason.Insufficient level of antifreeze in the cooling system.
• 🌀 Reason.: Breakdown of the water pump (check the jet from the control hole).

DecisionWash the cooling system with a special liquid (for example, Liqui Moly Kuhler-Reiniger), replace the thermostat (original art. 388-50311-1).

3. Power loss at high revs

• ⛽ Reason.: Injection nozzles clogged (ultrasound cleaning required).
• 🔧 Reason.Wear of piston rings (check compression - normal) 10–12 kg/cm2).
• 🎛️ Reason.: The ignition angle is incorrectly configured.

DecisionDiagnostics at the stand (cost ~ 3000 rubles), replacement of rings when running more than 1,500 hours.

⚠️ Attention.: If the engine starts to "treat" (uneven work), do not delay the diagnosis. 80% of the time it is associated with the problem of the car. topping up (original article - 388-82546-1Their replacement will cost 2,500 rubles, and ignoring the problem leads to the failure of the ignition coil (price ~ 12,000 rubles).

Tuning and accessories for Tohatsu MFS40A

Standard equipment Tohatsu MFS40A It includes everything you need to operate, but many owners customize the engine to suit their needs.

• 🎣 Trolling regime: Installation of a separate control unit Tohatsu Troll Control (art. 388-85345-1) allows smoothly adjusting the speed from 600 to 1000 rpm - ideal for fishing on a predator.
• ⚡ Spark amplifier: Module MSD Marine Ignition Increases spark power by 20%, which improves cold start and reduces fuel consumption by 3-5%.
• 🛡️ Defending lower unit: Anode plates of magnesium alloy (for example, Mercury 8M0078368) prevent corrosion when used in salt water.
• 📡 Hydraulic control:Kitt Tohatsu Remote Control (art. 388-85876-1) replaces the cable system, making the control smoother.

For lovers of long hikes, the installation is relevant fuel-tank capacity of 25-50 l (for example, Moeller 032501This increases the autonomy to 12-15 hours at cruising speed. Remember, the tank must be certified to the standard. ISO 10088 It's equipped with a pressure relief valve.

Tuning of the exhaust system (for example, the installation of "direct flow") on Tohatsu MFS40A It's not practical -- it's only 1-2 hp, but it's going to increase noise and reduce engine life. pitch-optimized screwThis motor is suitable for:

• Michigan Wheel Apollo (Step 13-15) for high-speed boats.
• Solas Amita 11–13 – For heavy boats with heavy loads.

Owner reviews: pros and cons

Analysis of feedback on forums (Fish-House.ru, BoatMag.ru) and on social media shows that Tohatsu MFS40A It's estimated to be 4.7 out of 5 on average.

Pluses (90% of owners are reported):

• ✅ Reliability: "No serious breakdowns in 5 seasons, only according to the regulations."
• ✅ Economy: “At 30 km/h, the flow rate is 8.5 litres per hour, 20% lower than the old one Mercury 40".
• ✅ Quiet work.“On singles, you can hardly hear, fish are not afraid.”
• ✅ Easy launch.: "Start from half-turn even at -5°C (subject to winter oil). 5W-30)".

Cons (Reports by 10% of owners):

• ❌ Weight."Heavy to carry alone, need a telescopic transom."
• ❌ Parts priceThe original water pump costs 8 000 rubles, but enough for 3 seasons.
• ❌ Difficulty of self-service: "To replace the belt of the HRM you need to remove the lid - without experience can not cope."

Interesting fact: among the owners Tohatsu MFS40A 60 percent use it for fishing, 30 percent for family walks, and 10 percent for towing skiers or wakeboarders, and the latter note that the motor is confidently pulling an adult on a wakeboard, but for a slalom, it is better to choose a model from 50 hp.

In the forums, people often ask about motorAccording to the service centers, subject to the TO regulations Tohatsu MFS40A It's fine.

• 🔧 Piston group: 2,000-2,500 motor hours.
• ⚙️ gearbox: 1,500-1,800 hours of motorized work (with regular oil change)
• ⚡ Ignition system: 3000+ motor hours (candles change every 300 hours)

FAQ: Frequent questions about Tohatsu 40hp four-stroke