The power selection unit for an inflatable vessel always begins with determining the type of engine, and PVC outboard motor with Two-Stoke Gasoline It remains one of the most popular solutions among water engines, driven by its unique combination of compactness, high specific power and simplicity of design, making it an ideal companion for fishermen and tourists, unlike four-stroke engines, such engines do not require complex maintenance and can operate in any position, which is critical when maneuvering in narrow ducts.
But newcomers often face myths about the gluttony and smoky nature of these units, and modern models from leading brands have learned to effectively burn the fuel mixture, minimizing harmful emissions. Yamaha, Tohatsu and Hidea They offer technologies that make it comfortable to operate even in enclosed waters, and the key is to understand the physics of the process: in a two-stroke engine, oil burns with gasoline, providing lubrication of rubbing parts.
In this article, we will discuss in detail how not to get confused in the specifications and choose the unit that will unlock the potential of your inflatable boat. You will learn about the nuances of running, the right proportions of the fuel mixture and the features of operating in real conditions. A competent approach to choosing will avoid costly mistakes and enjoy every minute on the water without unexpected breakdowns.
Advantages and Disadvantages of Two-Track Scheme
Why? two-stroke The answer is design: here the cycle takes one turn of the crankshaft, whereas a four-stroke takes two, which provides a sharper response to the gas handle and better thrust at low revs, which is especially valuable when going into planing under full load.
In addition, the weight of the unit is often 30-40% less than that of a four-stroke equivalent of the same power. For owners of light PVC boats, this is a crucial factor in maintaining mobility and the ability to transport the engine in the trunk of a passenger car. The lack of a crankcase with oil simplifies the design, making the engine less sensitive to rolls and pitching.
⚠️ Warning: Two-stroke engines are sensitive to the quality of the fuel mixture. Using pure gasoline without adding special oil will lead to bullies of the piston group in minutes.
But the medal has a downside. Fuel consumption It's actually higher, and the exhaust gases are more unburned hydrocarbons. Noise is also a feature, although the new generation of mufflers today are much quieter than their predecessors from the 90s.
- 🚀 High specific power and fast set of turns.
- ⚖️ Less weight compared to four-stroke analogues.
- 🛠️ Simplicity of design and the possibility of self-repair.
- 💰 More affordable cost of purchase and maintenance.
It is worth noting that the two-stroke scheme allows the engine to be operated in any position, which is impossible for four-strokes where oil is in the crankcase, making them indispensable for boats, which are often used in extreme conditions or in shallow waters where a sharp roll is possible.
Power selection: 2 to 20 hp
Picking up cock-boatExcessive power can lead to the destruction of the transom or, worse, to the loss of stability of the vessel during a sharp start. For single boats up to 3 meters in length, 2-5 hp units are usually sufficient.
For family holidays and fishing, the two best choices will be models in the range of 9.9-15 hp They confidently lead the boat with two passengers and equipment to planing, ensuring a comfortable speed. More powerful versions, such as 18 or 20 hp, are designed for heavy boats NDNDM or for those who appreciate maximum dynamics.
The length of the lower unit is also an important parameter: inflatable boats are most often used short leg (S), because the transom is located quite high, the installation of the motor with a long leg (L) will require additional improvements or lead to inefficient operation of the propeller.
And remember to consider the weight of the engine, and if you plan to drag it along the shore often or down a steep slope, every kilogram will make a difference. The difference in weight between two-stroke and four-stroke motors of equal power can reach 15-20 kgThis is a significant argument in favor of two-tact.
- 🎣 2-5 hp - for quiet fishing and single boats.
- 👨👩👧 9.9-15 hp – a universal choice for family and tourism.
- 🏎️ 18-20 hp - for heavy boats and high-speed walks.
Fuel mixture: proportions and quality of fuel
The most critical moment in the life of the owner of a two-stroke is the preparation of a fuel mixture. Gasoline must be fresh, octane number not lower than the AI-92, and ideally - AI-95. Using old fuel that has stood for more than a month can lead to oxidation and the formation of resins that will clog the carburetor.
The oil must be specifically designed for two-stroke water-cooled engines and be labeled TC-W3Automotive oils or air-cooled liquids (for example, for chainsaws) are categorically not suitable here, as they form a deposit and disable the engine.
⚠️ Warning: Never pour oil directly into the tank without first mixing it in a separate container, which will lead to uneven lubrication and the risk of overheating the cylinder.
The mixing proportions depend on the engine model and the manufacturer's recommendations: the classic ratio for running is 1:25, and for continuous use is 1:50, which means that for 1 liter of gasoline you need to add 20 ml or 40 ml of oil, respectively.
Use a transparent measuring cup or syringe to accurately dosing the oil. It is almost impossible to determine the correct proportion by eye, and an error can be fraught with engine repair.
Mixing the components is best in a separate canister, actively stirring it before each refueling, which ensures uniformity of the mixture and uniform lubrication of all engine components. Do not store the finished mixture for more than two weeks, as it loses its properties.
New motor break-in process
Running is not a formality, but a necessary process of working out rubbing parts. New engine Ignoring this phase reduces engine life by many times and can cause denial of warranty service.
The first start is better to make on a stand with a barrel of water or immediately on the water, but with observance of the speed mode. In the first 5-10 hours of operation, it is not recommended to give full gas.
☑️ Engine break-in plan
The piston rings and cylinders are laundered during the break-in, and if you put too much stress on the cylinder, the micro-strains of the metal can cause bullies, and vice versa, working only at idle speeds will not provide the necessary load for quality workouts.
After the first 10 hours of the motor, it is recommended to replace the fuel filter (if there is one in the system) and check the tightening of the fasteners, which may have weakened from vibration.
What happens if you don't run the engine?
Ignoring the break-in can cause the piston to jam in the cylinder at full speed, due to local overheating and expansion of the metal that has not yet taken its final shape, in which case repair will be expensive and difficult.
Maintenance and storage
Your durability boat-engine After each operation, you need to flush the cooling system with fresh water, especially if you've been swimming on a salty pond or in a murky river, and this will prevent the cooling shirt from corrosion.
When you put it in long-term storage, for example, in the winter, you need to conserve the engine. To do this, you need to produce all the gasoline from the carburetor or add a fuel stabilizer to the tank. It is also recommended to remove the candle and pour several blocks of engine oil into the cylinder, turning a crankshaft.
| Interval | Action. | Importance |
|---|---|---|
| Every exit | Visual examination, washing | High. |
| 10 motor hours | Candle check, bolt check. | Critical |
| 50 hours of motorsport | Replacement of the fuel filter | Medium |
| 100 motor-hours | Decompression, compression check | High. |
Store the engine upright so that oil does not leak into the muffler and carburetor. The ideal place is a dry, ventilated room. If this is not possible, use a special case, but make sure that the engine is completely cooled before packing.
Regular flushing of the cooling system with fresh water prolongs the life of the water pump and prevents the engine from overheating at the most inopportune moment.
Comparison with four-stroke analogues
The perpetual debate: which is better, two-stroke or four-stroke? For PVC boat owners, the answer is often in favor of two-stroke because of weight and transportability. Four-stroke engines are heavier, have an oil crankcase that cannot be tilted more than 25 degrees, and require more complex maintenance.
But four-strokes are more economical, quieter and more environmentally friendly, and they don't require a mixture, which makes it easier to operate, but for boats up to 3.6 meters long, a four-stroke engine can weigh up to 70 percent of the boat's payload, making it inappropriate to use.
If you use a boat for professional fishing, where silence is a key factor in success, a four-stroke can be justified. petrol-engine The king of small water, offering the best balance of price, weight and performance.
- 🔇 Four-strokes are quieter at idle speeds.
- ⛽ Two-strokes require mixing oil and gasoline.
- 🎒 Two-strokes are much easier to carry.
- 💸 Repairing two-strokes is cheaper.
Frequently Asked Questions (FAQ)
Can I use a two-stroke motor on a boat without a transom plate?
It is possible to use a motor without a transom plate, but it is not recommended for high-power models. For motors up to 5 hp, it is permissible to install on the inflatable side using special mounts. For more powerful units, the absence of a rigid transom will lead to the destruction of the mounting and a potentially dangerous situation.
Which petrol is better to fill: 92nd or 95th?
Most modern two-stroke engines are designed for AI-92 gasoline. the use of AI-95 does not give a significant increase in power, but can be justified in hot weather or at high loads, since fuel with a higher octane number is less prone to detonation.
Why does the engine smoke at idle speed?
Smoke on idles is normal for a two-stroke engine, as the mixture is rich in oil and combustion is inefficient at low temperatures. If the smoke turns black or blue when loaded, this may indicate an improperly prepared mixture or problems with the carburetor.
Do I need to drain water from the pump for the winter?
Yes, it is. Residues of water in the cooling system will expand when frozen and can split the pump or pipe body. After the last season, let the engine run for a few seconds without water (only to remove residues) or blow the system with compressed air.