Modern water-motor sport and amateur fishing are unthinkable without a high-quality watercraft that can quickly deliver to the fishing site or provide a comfortable rest on the water. flyboats They have become the gold standard for thousands of owners, combining ease of transportation, reliability of design and affordable cost, and unlike heavy metal counterparts, they can be transported in the trunk of a passenger car, dramatically expanding the geography of water bodies to visit.
However, despite the apparent simplicity of the design, choosing a kit "boat plus engine" requires a deep understanding of the technical nuances. lower unit Or a mistake in the calculation of the load capacity can turn a walk into a dangerous adventure, and in this article we will discuss in detail all aspects of the selection, assembly and operation of small PVC vessels, so that your launch was exceptionally pleasant.
It is important to understand that the market offers many solutions, from the simplest rowing models to high-speed planing complexes. The key safety factor is compliance with the engine power limit specified by the manufacturer in the product passport. Ignoring this parameter is a direct way to break the transo or, worse, to lose the stability of the vessel on the wave.
Classification of inflatable boats by design and material
The basis of any inflatable boat is the material of cylinders, which must withstand mechanical stress, ultraviolet radiation and temperature changes. PVC (polyvinyl chloride)It's a multi-layered fabric with a synthetic cord, and unlike simple rubber, high-quality PVC is not rotting and has a high puncture resistance, which is critical when landing on a rocky shore.
Structurally, all models are divided into two main types: flat-bottomed and keel. Flat bottom is characteristic of small boats designed for calm water and fishing in plumb. Kiel models with an inflatable or hard keel provide better germination on the wave and course stability, which is indispensable when driving with a high speed. outboard at high speeds.
- 🛶 The flat bottom is ideal for quiet lakes and the use of electric motors.
- 🌊 The keel design provides comfortable ride on the wave and planing.
- 🪵 Hard floorboard (plywood or aluminum) gives the necessary rigidity to the body.
When choosing, you should pay attention to the density of the fabric, which usually varies from 750 to 1150 g / m2. denser materials are used for boats designed for powerful engines and difficult operating conditions. Also important is the quality of the seams: they can be glued or welded, with the second option considered more reliable and durable in an aggressive environment.
Types of bottom and their impact on driving performance
The hardness of the bottom is what distinguishes a full-boat from a simple inflatable mattress. Depending on the design, the bottom can be soft (NDND), hard plywood or aluminum. Low pressure inflatable floor (NDD) is a complex structure with vertical internal partitions that, when pumped, create a rigid plane, which allows you to assemble the boat without using heavy floorboards, which significantly reduces the overall weight of the kit.
Plywood floorboards are typically made of water-resistant plywood and are connected by profiles, which offer excellent stiffness and the ability to install more powerful engines, but require more time to assemble and dry after use. Aluminum floorboards are lighter and stronger than plywood, do not absorb moisture or rot, but they cost much more.
⚠️ Attention: When using plywood floorboards, be sure to check the condition of the lacquer coating and docking profiles. The intrusion of sand between the elements can lead to wiping of the bottom material and depressurization.
Secrets of assembling a solder boat
When assembling a boat with a hard floorboard, start laying sheets from nose to transom, which will avoid the formation of a hump in the middle, which is difficult to straighten before installing the cylinders.
The choice of bottom type directly affects how the boat will behave under load. For fishing in reeds or in shallow water, a soft bottom is often chosen, which is less susceptible to damage from snags. For open water and high-speed movements, rigid structures are preferable to ensure stability of the course.
Choice of outboard motor: two-stroke or four-stroke?
The heart of your boat is the engine, and here before the buyer there is an eternal question of choosing between two-stroke (2T) and four-stroke (4T) engine. Two-stroke engines They are traditionally lighter, cheaper and easier to maintain, and they are not afraid of long-term full-speed operation and can be transported in any position, making them ideal for small- to medium-sized PVC boats.
Four-stroke engines, by contrast, are fuel efficient, low noise and no need to mix gasoline with oil. However, their weight is much higher, which can be critical for inflatable boats with limited capacity. In addition, 4T engines are sensitive to roll when transported and require strictly vertical storage.
- ⚙️ 2T engines require the preparation of a fuel mixture (gasoline + oil).
- ⛽ 4T engines run on pure gasoline, oil is in the crankcase.
- 🔇 Four-strokes are quieter and more environmentally friendly, but heavier than their counterparts.
When choosing power, you should be guided not only by the desired speed, but also by the specifications of the transom. For a two-seater boat with a length of 320-340 cm, the optimal motor is often 5-9.8 hp If you plan to get on the water with passengers or cargo, the power reserve will only be a plus, allowing you to feel more confident on the wave.
Transcript board and motor mounting
The transom is the only rigid part of an inflatable boat that carries all the load from the engine's thrust, and it's a board that's waterproof and protected by layers of PVC. transom board The removable version is convenient for compact packaging, but the glued transom provides better stiffness of the stern and simplifies the installation of additional equipment, such as a sonar.
The most important parameter is the height of the transom, which is standard 381 mm (15 inches) for a short lower unit leg. Installing a motor with a longer leg on a low transom will lead to cavitation and loss of traction, and too short a lower unit will cause the propeller to capture water and overheat the engine. To adjust the height of the motor on the transom, additional linings are often installed or adjustable fastenings are used.
Mounting the motor is carried out with the help of rods, which must reliably fix lower unit. Rubber linings The rods protect the transom tissue from rubbing and damage, and when installing the motor, you need to make sure that the screw does not touch the bottom of the boat even at maximum differentiation.
☑️ Checking the transence before exit
⚠️ Attention: Never try to start the engine unless the boat is anchored on water or on a hard surface. The propeller's operation in the air or on land can cause lower unit to collapse and injury.
Compatibility and power selection table
The right combination of boat weight, engine power and lower unit length is key to safe operation. Boat manufacturers always specify the maximum permitted engine power, exceeding this limit can lead to transomper destruction, loss of stability and even tipping the boat.
Below is an indicative compatibility table to help you navigate your choices, but always remember that the final decision should be based on the specific model’s technical documentation.
| Boat length (cm) | Type of bottom | Max power (hp) | Recommended motor |
|---|---|---|---|
| 280 - 300 | NDNDM/Pyol | 3.5 - 5.0 | Tohatsu M5BDS, Suzuki DF5 |
| 320 - 340 | Pyol/NDM | 9.8 - 15.0 | Yamaha 9.9GMHS, HDX T15 |
| 360 - 380 | Pyol/NDM | 15.0 - 25.0 | Mercury F20, Tohatsu M25 |
| 400+ | NDNDM/Pyol | 30.0 - 50.0 | Suzuki DF40A, Yamaha F40 |
When operating in planing mode, it is important to correctly configure differentiator The slope of the lower unit is controlled by a pin in a brace, so if the bow of the boat is too high, the speed drops, and if it is buried, there is a risk of flooding the water into the cockpit.
For better acceleration dynamics, set the engine anti-cavitation plate in one line with the bottom line of the boat or 1-2 cm lower when fully loaded.
Safety and maintenance of the kit
Operating inflatable boats requires a set of safety rules that are often ignored by beginners, first of all, the availability of life jackets for everyone on board, even if you are a great swimmer, hitting a transom who lost control of the engine or sudden cramp can cost lives.
Regular maintenance prolongs the life of your equipment, and after each release, especially in salt water, you need to wash the engine and boat with fresh water. PVC It should be wiped from dirt and dried before packaging to avoid mold and unpleasant odor.
- 🔧 Regularly check the tightening of bolts on lower unit and Strubkins.
- 🧼 Wash the boat with mild detergents, avoiding aggressive chemicals.
- 🌡️ Keep the equipment in a dry place at a temperature not lower than -15 C.
Pay special attention to the condition of the valves and seams. Periodically check the boat for air etching, dipping the inflated compartments into water or treating with soap solution. Timely detection of a micropuncture will eliminate it in the field without serious repair.
⚠️ Attention: Do not leave a pumped boat in direct sunlight for a long time unnecessarily. The air pressure inside the cylinders increases when heated and can exceed the permissible limits, damaging the seams.
The main secret of the longevity of an inflatable boat is complete drying before packaging and storage in a straightened form or in a free bag, rather than tightly folded.
Frequently Asked Questions (FAQ)
Can I put a four-stroke engine on a small inflatable boat?
Technically, you can, if the transom can withstand the weight of the engine and the total load capacity of the boat is not exceeded. However, for boats up to 320 cm in length, the weight of the 4T engine is often excessive, which impairs the driving performance and makes the boat roll. The optimal use of 4T on boats from 340-360 cm.
What pressure should be in the cylinders and keel?
For most PVC boats, the operating pressure in cylinders is 0.2-0.25 kgf/cm2 (or up to 250 mbar). The inflatable floor (keel) is usually pumped to 0.3-0.4 kgf/cm2 to ensure rigidity. Pumping is dangerous by breaking seams in the sun, under-pumping leads to deformation of the hull.
How to seal a puncture in a boat in the field?
For emergency repairs, use a remix that comes with the boat. The surface needs to be degreased, glued (usually polyurethane), waited until the specified time, and tightly pressed patch. The hot gluing method is often used in the workshop for reliable repairs.
Do I need to register an inflatable boat with an engine?
Registration with GIMS is mandatory if the mass of the equipped vessel with the engine exceeds 200 kg, or if the engine power exceeds 8 kW (about 10.88 hp). If the engine is weaker than 10 hp and the total weight is less than 200 kg, registration is not required, but the availability of documents for the boat and the engine is desirable.