Choosing a power unit for an inflatable boat is always about finding a balance between weight, power and cost of ownership. outboard motors up to 5 horsepower They occupy a special niche in this segment, being the most popular solution for owners of small boats, and it is this power limit that allows you to operate a vessel without having to have rights to operate a small vessel, which greatly simplifies the life of the driver.
But don't think that low power means no power. PVC boat It's not just a quiet fishing experience in the reeds, but also a full walk in the reservoir, and it's all about getting the right specifications for your specific tasks.
In this article, we will discuss all aspects in detail: from the technical nuances of two-stroke and four-stroke engines to the peculiarities of their transportation and maintenance. 5 hp is the maximum power, allowing you not to register the engine in GIMSWhether to chase beyond this limit or better to choose something less powerful.
Why 5 horsepower: legal and practical aspects
The main argument in favor of buying a motor with a capacity of up to 5 hp is legislation: according to the rules of registration of small craft, engines with a capacity of up to 8 kilowatts (which is exactly 5 hp) do not require registration and obtaining license plates, which saves the owner from annual payment of state duty, passing a technical inspection and the need to take examinations for rights.
In addition to the legal advantages, there is a purely physical aspect. Motor weight In this class, it typically ranges from 16 to 25 kilograms, which allows one person to easily lift the unit on board or carry it from car to water, and in comparison, more powerful models weigh significantly more, which often requires a winch or a partner.
Economically, it's cheaper to maintain, fuel consumption is minimal, and the cost of spare parts and consumables (candles, oil, filters) is much lower than the older brothers.
However, there are limitations to consider: on large and heavy boats, such a motor will not be able to bring the boat to planing, and you will have to be content with displacement mode, in which case the speed rarely exceeds 8-10 km / h.
- 🚤 No need to register with GIMS and obtain a license.
- ⚖️ Low weight, which allows you to easily transport the engine to one person.
- 💰 Low fuel consumption and cheap maintenance.
- 🔇 Relatively low noise level compared to the powerful analogues.
⚠️ Attention: When buying a motor marked as 5 hp, be sure to check the technical data sheet. Sometimes manufacturers indicate power with a margin, and the documents may appear the figure of 6 hp, which will already require registration.
Two-stroke or four-stroke: the eternal dilemma of the angler
When choosing a motor up to 5 hp, the buyer faces the question of the type of engine. Two-stroke engines (2Ts) are traditionally cheaper, easier and easier to repair, and they run on a mixture of gasoline and oil, which requires the owner to prepare the fuel mixture before each refueling, but their design provides excellent traction at low revs.
Four-stroke engines (4Ts) run on pure gasoline, oil is in the crankcase and changes periodically, like in a car. They are quieter, more economical and more environmentally friendly. But these benefits come at a cost: four-strokes are 30-40% heavier than two-stroke counterparts of the same power, and they are also more expensive to buy.
For fishing, where silence is important, the four-stroke option is preferable. The characteristic sound of a two-stroke fart can scare off fish, whereas the 4T runs smoothly and quietly. In addition, four-stroke engines do not require constant mixing of fuel, which is more convenient.
It is worth noting that modern two-stroke motors The choice of leading brands has also become significantly cleaner and more environmentally friendly thanks to combustion technologies, often boiling down to the priority of weight and price (2T) or comfort and silence (4T).
- 🛠️ 2T: Simple design, no crankcase with oil, can be transported in any position.
- 🛢️ 4T: You need to carry strictly vertically, otherwise the oil will get into the cylinder.
- 🔊 Noise: 4T is much quieter, which is critical for trolling and catching in quiet backwaters.
Key specifications: what to look at first
When studying catalogs, it is important to pay attention not only to horsepower. Motor weight If you plan to often pull the boat ashore or drag the engine over obstacles, every kilogram counts, and models weighing up to 20 kg are considered the "gold standard" for this class.
The length of the lower unit (legs) also matters. For inflatable boats, standard length (S) is usually sufficient, but if you have a boat with a high cylinder or converted to a motor, you may need a long leg (L). Wrong choice will lead to cavitation (air capture) and loss of traction.
The presence of neutral and ignition system is another important point: Motors under 5 hp are often equipped with a manual starter (drag starter), as the electric starter will significantly weight the design and require a battery. However, some models have electronic ignition, allowing easy start in all weather.
When choosing a PVC outboard motor, pay attention to the presence of rubberized mounting (transe fastener). Hard metal can damage the transom board of an inflatable boat when vibrating.
The table below shows a comparison of the popular specifications of motors of different types in the class up to 5 hp.
| Characterization | two-stroke motor | four-stroke engine |
|---|---|---|
| Weight (roughly) | 17-21 kg | 24-28 kg |
| Fuel consumption | 1.5 - 2.0 l/h | 0.8. 1.2 l/h |
| Transportation | In any situation | Strictly vertically |
| Noise | High. | Low. |
Overview of popular models and brands
The market of motor equipment is saturated with offers, but leaders in the class up to 5 hp remain time-tested brands. Yamaha and Tohatsu They're known for their indestructibility and their stable performance over the years. Yamaha 2CMHS It is a legend that has not changed its design for decades.
Chinese manufacturers, such as Hangkai and ParsunThey offer more affordable alternatives, often copies of Japanese engines assembled under license, and build quality can vary, but when maintained properly, they last a long time and save you money.
European brands, for example, Swedish Johnson (now production is often moved to Asia, but quality control remains) or German developments, often focusing on sustainability and ergonomics, depending on the availability of service centers in your region.
Should I buy a used motor?
Buying a used motor is a lottery. Two-strokes are less cranky to storage, but it's important to check the compression. Four-strokes require oil checks and no rust inside the exhaust system. If the engine has been standing for a long time without canning, repairs may exceed the cost of buying.
When buying, be sure to check the equipment. Some manufacturers sell engines without a screw or without tools in the kit, which becomes an unpleasant surprise on the water.
Rules of running and first start
The service life of any engine depends on how it passed. first-runIgnoring this stage is the surest way to get the piston group bullies and quickly fail, and the breaking in process is essential to grinding all moving parts.
Normally, it takes about 10 hours to run, the first couple of hours the engine has to run at idle speed or with minimal load, and then the load can be gradually increased, but not fully throttled until the scheduled time has expired.
☑️ Checklist before first launch
Working on a "dry" or in a barrel without proper water pressure can lead to overheating and deformation of the impeller pump.
⚠️ Attention: Never run the motor out of water without connecting an external source of water under pressure, and even a few seconds of dry operation can destroy the rubber impeller of a water pump.
Transportation and storage: nuances of operation
Transporting the engine to 5 hp is usually easy because of its light weight, but it has its own specifications: two-stroke models can be transported in any position, which is convenient when you put in the trunk of the car. Four-strokes require a strictly vertical position or stacking on a special side so that oil does not leak into the combustion chamber.
For off-season storage, you need to conserve. For two-stroke engines, it is recommended to extract the residue of fuel from the carburetor so that the resinous deposits do not clog the jellybras. Four-stroke engines require oil change before long-term storage, since the work contains acids that destroy metal.
Keep the engine in a dry room, removing from the boat. If this is not possible, use a protective case, but provide ventilation so that the inside does not accumulate condensation, causing corrosion.
Proper preservation for the winter extends the life of the engine by 30-40% and ensures an easy start at the beginning of the next season.
Frequent breakdowns and methods of their elimination
Despite the simplicity of the design, engines up to 5 hp also break down. The most common problem is the difficulty of starting. Often the cause lies in the spark plug: it can be filled with fuel or covered with carbon, Regular inspection and cleaning of the candle solve most problems.
The second most common malfunction is overheating, which is caused by debris entering the intake or by a break in the impeller pump, and if the engine is running but the water from the control hole is not coming (or is coming in a weak stream), you need to immediately turn off the engine and clean the cooling system.
Carburetor problems often occur when using poor-quality gasoline or improper storage. If the engine stalls when adding gas, most likely, cleaning the jellybers and adjusting the fuel level in the float chamber are required.
- 🔧 Candle: Black loam is a rich mixture, white is poor or overheated.
- 🌊 Pomp: The absence of a jet of water is a sign of clogging or wear of the impeller.
- ⛽ Fuel: Use of old gasoline (older than 3 months) leads to the formation of resins.
The final choice: what to buy right now
In summary, it can be said that outboard motor up to 5 hp It's the perfect choice for a novice motorized boatmaster, combining enough power to move comfortably, ease of handling, and no bureaucratic hurdles, and a workhorse for fishing, hunting, and water recreation.
If you have a budget, you can use a proven two-stroke from a Chinese manufacturer with good service support, and if comfort, silence and you're willing to pay less for gasoline, a four-stroke model is the best investment.
The main thing is not to save on maintenance and fuel. Quality oil and good gasoline will pay off with the long life of your "iron friend." Good shopping and seven feet under the keel!
Can I increase the engine power to 5 hp to 6 or 8?
Technically, many motors have a hidden resource, and removing the throttle limiter gives you power gain, but this cancels the warranty, increases fuel consumption and, most importantly, makes the engine a GIMS registration requirement, which will result in fines for inspection.
FAQ: Frequently asked questions
Do I need to register the 5 hp engine in GIMS?
No, motors up to 5 hp (inclusive) are not subject to mandatory registration if the total weight of the vessel with the engine does not exceed 200 kg.
What kind of oil to use into a two-stroke engine?
Use special oil for two-stroke outboard motors labeled TC-W3. Automotive oils or chainsaw oils (JASO FD) can lead to the formation of soak and failure.
Why does the engine stop at high speeds?
Most often, this indicates a clogging of the fuel jelly, water entering the fuel tank or a leaky fuel hose, and the cause may be due to the incorrectly exposed gap of the candle.
Can I refuel a four-stroke engine with AI-92 gasoline?
Yes, most modern four-stroke engines with a capacity of up to 5 hp are designed to work with AI-92 gasoline. The use of AI-95 is allowed, but is not mandatory and does not give an increase in power.