Choosing a first or additional engine for small boats often leads a potential buyer to study the range of the Japanese brand. TohatsuExactly. boat-engine Tohatsu 5 It is considered one of the benchmark solutions in the 5 horsepower class, combining legendary reliability and simplicity of design, and many anglers and water lovers are looking for this model because of its light weight and ability to plane even with a small load.
Unlike its more powerful counterparts, the unit does not require a driver's license to drive, making it attractive to a wide range of users, but behind its external simplicity lies a complex engineering idea that requires the right approach to service. It is critically important to observe the proportion of the mixture of oil and gasoline during the break-in period, since it is the first tanks that determine the resource of the piston group. In this article we will analyze all the nuances of operation, technical features and secrets of longevity of this popular "Japanese".
It is worth noting that the outboard motor market is saturated with analogues, but Tohatsu MFS5C Or two-stroke versions of it remain the top sellers for a reason, the quality of aluminum casting and assembly accuracy are at the highest level here, and if you plan to use the technique for trolling or frequent trips over short distances, you need to understand the specifics of the carburetor system and the ignition system.
Technical specifications and design features
Considering boat-engine Tohatsu 5 The average weight of the device is about 20-21 kg, making it easy to transport in the trunk of a car or even carry it by hand to one person. The design of the lower unit is made of a durable aluminum alloy that is resistant to corrosion in salt water.
The heart of the device is a single-cylinder two-stroke engine with a volume of 93 cubic centimeters. This configuration provides excellent traction at low speeds, which is critical for heavy PVC boats or metal "kazak". The CDI (Capacitor Discharge Ignition) ignition system guarantees stable spark formation even with a discharged battery or its absence, since the engine is equipped with built-in magdino.
- 🔹 Engine type: Two-stroke, single-cylinder with forced air ventilation.
- 🔹 Start system: Manual (starter), thrust is located ergonomically.
- 🔹 Control: Vomit (toler), allows you to control the direction and gas.
- 🔹 Cooling: Off-shore water through an open-cycle pump.
Special attention should be paid to the exhaust system. Tohatsu 5 hp Technology has been applied to reduce noise and vibration, making the boat more comfortable. Silencer It's integrated into the lower unit, and the exhaust is through the screw hub or above the waterline, depending on the mode of operation, and it also helps to cool the inner cavities better.
Fuel consumption and efficiency of operation
One of the main issues that concern owners is the real appetite of the engine. Tohatsu outboard motor 5 It is famous for its moderation, but the figures can vary depending on the style of driving and loading the vessel. On average, full gas (full throttle) consumption is about 1.5-1.8 liters per hour.
To calculate the range, you need to consider the volume of the built-in fuel tank, which in this model is usually 1.1 or 1.2 liters. This volume is enough for about 45-60 minutes of active operation at maximum speeds. If you plan long transitions, it is recommended to purchase an additional external tank, although for most tasks of the fishing class, the regular volume is enough.
Use a quality 92nd or 95th gasoline with an octane number not lower than the stated in the instructions. The use of fuel with an expired shelf life can lead to clogging of the jelly carburetor with resinous deposits.
Economics also depends on the state of carburetor Factory settings are usually optimal for medium-sized conditions, but when operating at high altitudes or in hot climates, adjustments may be necessary. Tohatsu M5B works smoothly, without failures with a sharp opening of the throttle.
breaking in process: step-by-step instructions
Quality break-in is the foundation of a long life for your engine, and neglecting this stage often leads to piston bullies and loss of compression. Tohatsu outboard motor 5 It requires strict adherence to the time intervals and proportions of the mixture, and the whole process is divided into several stages, each of which has its own load specifications.
The first 10 minutes of work should be idle. Don't try to get full gas right away, even if the boat seems light. At this time, the piston rings are lapped against the cylinder walls. Then there is a stage of working at low and medium speeds (up to 50% power) for 50 minutes. Only after that you can briefly go full gas.
☑️ Checklist for break-in preparation
The most important aspect is the fuel mixture. Tohatsu During the break-in period, it is recommended to use a ratio of 1:25 (40 ml of oil per 1 liter of gasoline). After the first 10 hours of operation (or 2-3 full tanks), you can switch to the standard ratio of 1:50, specified by the manufacturer for permanent use.
⚠️ Attention: Never keep the engine running at idle speeds for a long time without load (on land or with a raised lower unit). This can lead to overheating and failure of the crankshaft coils, as the flow of off-board water for cooling will be insufficient.
Carburetor adjustment and idling adjustment
Stable operation of the engine at low revs - the guarantee of safety and comfort. boat-engine Tohatsu 5 It is deaf when discharged or unstable, requires adjustment of the carburetor, the main adjustment elements are the screws of quality and quantity of the mixture, access to which is often closed by plugs to prevent unskilled intervention.
To adjust the engine, it has to be warmed to operating temperature. The idle screw allows you to set the speeds at which the engine is running steadily, but the boat is not yet starting to move. If the mixture is too poor, the engine will stall when the valve is opened sharply; if it is rich, there will be swelling on the candle and the exhaust smoke will increase.
The adjustment process requires accuracy and understanding of the principles of the ICE. It is recommended to adjust only with a tachometer in order to accurately set the speeds according to the specification (usually 900-1000 rpm for idling).
Secrets of setting up a carburetor
If the mix quality screw has a plastic limiter, do not try to dismantle it by force. Often enough to twist the screw to the standard number of revolutions (usually 1-1.5) to achieve an acceptable result without breaking the factory seals.
Table: Comparison of specifications with competitors
To better understand the place of the model in the class, it is worth comparing it with similar offers from other manufacturers. Tohatsu outboard motor 5 It often wins in weight and ease of maintenance, but loses in noise level to some four-stroke models, which, however, are much heavier.
| Parameter | Tohatsu M5B (2T) | Yamaha 5CMHS (2T) | Honda BF5 (4T) |
|---|---|---|---|
| Power (hp) | 5.0 | 5.0 | 5.0 |
| Weight (kg) | 20.0 | 21.5 | 25.5 |
| Type of engine | two-stroke | two-stroke | four-stroke |
| Volume (cm3) | 93 | 93 | 100 |
As you can see from the table, Tohatsu Four-stroke counterparts like Honda are quieter and more economical, but their weight can become critical for lightweight inflatable boats, where every extra piece of cargo matters.
Frequent malfunctions and methods of their elimination
Despite the high reliability, the equipment can fail, and the most common problem is the lack of a spark or difficulty starting. spark-plateIf it's wet and black, it's the problem with the re-enriched mixture or the quality of the oil, and if it's dry, it doesn't get into the cylinder.
Another common situation is overheating. If you notice that there is no water coming from the control hole, immediately turn off the engine. The cause may be a foreign object (grass, sand) getting on the water intake or a break in the impeller pump. Regular replacement impeller (once in 2-3 seasons) will eliminate most of the cooling problems.
- 🔸 Engine does not start: Check for spark and fuel intake.
- 🔸 The engine loses power: Clean the fuel filter and check the condition of the candle.
- 🔸 Strong vibration: Check the screw balance and no damage to the lower unit.
⚠️ Attention: When replacing the impeller pump, be sure to use a special lubricant for rubber parts. Dry running of a new rubber impeller is guaranteed to knock it out for even a few seconds.
Regular prevention (replacement of oil in the gearbox, lubrication of slits, washing of the cooling system) is 10 times cheaper than overhaul of the engine after a critical breakdown.
Frequently Asked Questions (FAQ)
Do I need to dilute gasoline with oil for Tohatsu 5?
Yes, since it is a two-stroke engine, mixing gasoline with a special oil for two-stroke engines (in a ratio of 1:50 after running) is a prerequisite for operation. Without oil, the engine will jam in minutes.
Which screw is better to put for a heavy boat?
For heavy boats or when fully loaded, it is recommended to use a screw with a smaller pitch (for example, step 5 instead of the standard 6), which will allow the engine to more easily get on plane and operate in the optimal range of revolutions.
Can I keep the engine on my side?
Long-term storage on the side is not recommended, since oil from the gearbox can flow into the cylinders through the coils, and fuel - flow from the carburetor. It is best to store the motor in an upright position or on a special stand.
Why does the engine smoke blue smoke?
Blue smoke is normal for a two-stroke engine, as the combustion chamber burns oil, but if the smoke becomes very thick and black, it may indicate an incorrect proportion of the mixture or problems with the carburetor.