Review of popular models of jet outboard motors

Jet engines often resemble the operating principle of a jet engine. The main difference is the flow of water coming from the water jet nozzle. The hole intended for drawing water into the watercourse is located in the lower part.

The water in the water jet is driven through the watercourse pipe thanks to an impeller, which helps to discharge the water flow. Passing through the screw, the flow accelerates and the resulting pressure splashes water through the nozzle, the diameter of which is quite narrow. A similar principle of motor operation sets the boat in motion.

Advantages and disadvantages

The main advantages of water cannons are:

• The device does not contain rotating parts that are located in the aquatic environment. This ensures that underwater vegetation and branches do not have a negative impact on the rotating movements of the impeller. You don't have to worry about vegetation getting wrapped around the auger, causing damage.
• Quick passage of shallow water and areas of the reservoir with a large number of snags and algae. Ordinary mechanisms rarely cope with such obstacles.
• Complete elimination of injury to a person swimming near the boat from the impeller , since it is located in the hull of the engine.
• The development of a high speed mode helps to increase the efficiency of the motor.
• Considering the complete contact of the bottom of the boat with the water, you can be confident in reliability and controllability even at high speeds. Even when taking sharp turns, the boat will be easy to control.
• The water cannon can easily cope with turns on the spot and can move forward with its side.
• Possibility of emergency braking with a minimum braking distance.
• A slight noise effect when moving , which will undoubtedly please any fisherman.

The main disadvantages of the motor can be considered:

• With the development of a low speed mode, the efficiency decreases.
• Water becomes an additional load for the boat , due to which the working process of the water jet occurs.
• Water in the engine tube has turbulence and reduces engine power.
• Despite the easy passage of shallow water areas , it is worth remembering that this provokes excess load on the rotor and stator. In this case, you should not count on a long service life.
• Repairing a water jet requires significant financial costs.

Design and principle of operation

The main components of a water jet are the propeller part and the engine (internal combustion). The water pipeline combines the following elements:

• water intake part - the front area that facilitates the movement of water to the screw part;
• a straightening hardware element that transforms the rotational movements of water flows into rectilinear ones;
• nozzle element;
• the tip of the tube through which water masses find their way out;
• a reversible steering device that allows you to change the direction of movement of the boat (both forward and reverse are provided).

Impellers (screw elements) can be of different types:

• The axial type is the simplest to manufacture, but the efficiency is low. In addition, the presence of the cavitation effect makes it possible to operate only at low speeds.
• Axial-diagonal type - designed for motors with an average number of revolutions. The efficiency level is slightly higher than that of axial impellers.
• Diagonal and auger are modern types of screws that are made using modern technologies. The main advantage of both types is a high level of efficiency and the ability to work with motors with high speeds.

The boat starts to move after jet thrust, which is created due to the ejection of water flow at high speed. A more detailed operating principle is as follows:

• Water flows penetrate the water intake, which is located in the front part of the craft. The water intake includes a mesh that can filter algae and floating debris. When designing a water intake, experts try to provide laminar flow to the water flow, which will significantly improve the overall performance of the motor.
• The impeller throws the water back , after which it enters the narrowed part, which further increases the speed of passage.
• The blades of the straightening apparatus are equipped with a peculiar shape that helps to provide slight resistance to the fluid that moves towards it. Straightening devices can be of various designs. The most popular of them is the scapular compression. It is this type of design that allows the straightening apparatus to simultaneously perform the functions of a nozzle device.
• Water flows enter the nozzle part (if the straightening device does not perform this function). The presence of a small flow area allows the flow pressure to be converted into velocity.

How to create an engine yourself?

Creating an engine with your own hands is not as difficult as it might seem at first glance.
Jet propulsors are usually made by fishermen based on the classic type engine design. The future product may be based, for example, on Chinese or domestic engine models (from 5L to 100L). Drawings of these structures are presented in the following form: To make a water-jet motor, you can use a classic standard gearbox: it must be attached to the main deadwood in the engine area. This is achieved by using a flange. After this, a metal blank is taken, where the design of the water intake, 6 blades and the water intake should be assigned.

To create a workpiece based on a standard design, a file and rollers are used. Afterwards, using the same tools, the product is processed. As a result of the work done, the workpiece receives the required shape. After this, the moment comes to weld the seams of the longitudinal and transverse types.

The water-jet structure must also acquire a hub: an area is allocated for this part in the location of the boss. The boat pump in its dry structure weighs twenty kilograms. However, the pattern of this product may occur in very rare cases. However, anyone can make a pump on their own, since there is quite a sufficient amount of instructional materials on the global network

It is also important to take into account that jet boats have a greater degree of profitability than boats with a simple engine

Jet outboard motors for inflatable boats are much easier to manufacture than for large boats with a jet engine. The main advantage is that almost any type of motor can be used for this type of boat, regardless of design. It is recommended for them to choose water-jet propulsors, the power of which ranges from fifteen to twenty hp.

The most suitable motor option for a boat is considered to be an outboard motor. Compared to a stationary motor, an outboard jet boat motor does not cover the useful volume of the boat and is easily dismantled. The device is characterized by low weight, high level of UM, simple design, and ease of use.

Positive and negative features

Water-jet propulsors are characterized by the following advantages:

• a good degree of protection from mechanical damage, as well as the ability to prevent cavitation;
• the vessel can pass through shallow water, overcome ponds that have become clogged, as well as other types of obstacles that protrude from the water. Water-jet propulsors here turn out to be more optimal than simple screw-type motors, in which the propeller or main motor may suffer;
• safety guarantee - the impeller is located in the inner part of the product and does not pose a danger to those people who are near the boat;
• water-jet outboard motors provide boats with greater stability and excellent controllability;
• water jet propulsion allows the boat or boat to turn right on the spot, as well as move forward on its side;
• the need to use reverse disappears, there is the possibility of sharp braking;
• lower hydrodynamic noise than that of screw propulsors.

• efficiency at low speeds is less than that of screw systems;
• the difficult process of transferring the water mass through the bottom of the water transport to the pump itself;
• the water intake functions like a pump, drawing in small debris from the bottom. Because of this, the cooling system may become clogged or the water pipe, as well as the impeller, may be damaged;
• high probability of rotor wear, because the vessel is operated in shallow water areas;
• expensive repairs;
• A jet boat can act up when moving slowly.

Choosing a water jet

When selecting a product of this type for a boat or boat, you must have information regarding 3 basic components of a watercraft:

In relation to the propulsion, these are traction characteristics, which depend on the degree of power of the engine itself, as well as on how fast the ship is moving.

Popular water jet models

Jet motors are manufactured by a small number of enterprises. The most popular brands of water cannons are:

YAMAHA (JET model range) truly produces high-end equipment. The power can be chosen at your own discretion, starting from 40 hp. and ending with 50 hp. The units are equipped with modern options, remote control, electric starter. The cost of motors with a high level of reliability is in the range of 250 thousand - 300 thousand rubles.

Squid – has a power of 2.5 hp. Can reach speeds of up to 15 km/h (depending on the type of boat). The device, having a high degree of reliability, is perfect for fishermen who use boats for fishing in small bodies of water. The cost of Squid does not exceed 60 thousand rubles.

Tohatsu - has a two-stroke engine and a power of 2.5 hp. The diverse model range also includes more powerful motors, the cost of which exceeds 50 thousand rubles. It develops speed quite quickly, which is undoubtedly a significant advantage.

Stalker is considered a representative of incredibly light engines. Their weight usually does not exceed 5 kg (dry condition). Can reach speeds of about 8.5 km/h. The gas tank holds 900 ml of fuel. The cost of a water cannon is in the range of 22-30 thousand rubles.

Self-installation of engines

Homemade water jet for a boat, created with your own hands on the basis of a centrifugal pump

Preparatory operations

This stage should be approached with all responsibility and attention. Only materials that meet technological requirements should be used

For example, let's take Pacer Pumps 200GPM Its body is made of heat-resistant polystyrene and weighs 18 kg. The engine is Intek, its power is 5 horsepower. The length of the head corresponding to this unit reaches 35 m. The cost is up to $300.

Manufacturing

• First. Install the pump in the boat.
• Second. Attach a two-inch PVC pipe to the suction side.
• Third. Lead the pipe into the water through a pre-made hole in the front of the bottom of the boat. At the end of it, install a pipe equipped with a filter. This design is a water intake.
• Fourth. Screw a fitting onto the thread of the pipe whose outlet diameter is 24 mm. Can be made from reinforced vinyl.
• Fifth. Make a nozzle from PVC pipe, its diameter should be the same as that of the fitting. The fitting is connected to the nozzle with a rubber hose.

Attention! The following technological step is erroneous: lower the nozzle into the water. This causes cavitation and a decrease in speed

Exploitation

This engine should be used on a boat that is about 3 and a half meters long. Take the length of the suction pipe to be 3 meters. Then the pressure of the water column will be approximately 20 meters, the pressure will be 2 atmospheres, and the speed can be reached up to 8 km/h. The main trouble: unscrewing the pressure fitting with a stream of water. To prevent this, it is better to build a separate mount for it or use a fitting with flanges.

How to make a water jet for a boat with your own hands based on a Veterok-12 boat motor with a flange

Manufacturing

• First. Place the water pipe inside the vessel.
• Second. Take the gearbox and secure it to the boat with a flange.
• Third. Make metal blanks for the shell, water collector and six blades using a file and bending rollers.
• Fourth. Carry out welding work to fasten the longitudinal and transverse seams of the drainage system and the water jet chamber.

Preparatory operations

Take any outboard motor with a power of up to 20 horsepower. It is best to try to purchase a light weight engine.

Next take:

• – gearbox
• – flange
• – hub
• - welding machine
• – development of the water collector
• – engine drawing
• – fittings
• – waterproof glue.

Manufacturing

The technological process is similar to installing a water jet for a regular boat.

Take the inlet part of the pipe approximately one and a half times larger in diameter than the water conduit. The design is made in accordance with the drawings, which, in turn, can be taken from the Internet.

Feedback about use

Alexander Vladimirovich, 48 years old I purchased a Kalmar engine a few months ago! The impressions are simply indescribable. After putting the motor on the boat, I began to swim across the Volga (which is almost 6.5 km) without any effort or delay. Not a motor, but a beast!

Nikita, 46 years old

My son gave me a Yamaha water cannon. My happiness knows no bounds! I can handle any body of water now – I can swim across it with ease. The boat moves almost silently, and when performing forced braking, the braking distance is very short, which is good news. Now I can enjoy fishing to the fullest.

Andrey Grigorievich, 54 years old Having ordered a Stalker motor on the Internet, I waited a long time for the order. As soon as I received it I immediately went fishing for testing. I'm pleased with the result. It develops a very decent speed in a short period of time and weighs very little.

Vladimir, 25 years old I’ve been using Kalmar for almost five years. During this time, not a single breakdown. Works like a clock. Crosses any distance with ease and speed! I think this is the best water cannon!

Yaroslav, 35 years old

I have been using a water cannon for quite a long time. Been to both large bodies of water and shallow waters and swampy areas. It works quite quietly, which does not frighten the fish at all. Fuel consumption does not exceed the permissible norm, acceleration is up to 11 km/h. I am very pleased with the motor and recommend it to all fishermen I know. The small weight of the equipment is also an important advantage. There were no complaints about the operation and I hope there won’t be any.

Nikita, 34 years old My father bought Squid several years ago. Apparently, he came across an unusable fake, since often the propeller wound up algae and the motor simply stopped working. Fishing brought absolutely no pleasure. I'm sinning with a fake, since my friends' Squids really don't cause any inconvenience to their owners. Coordinated work is pleasing, and breakdowns are practically not a concern.

Installation

Water cannons must be installed on fast (light) vessels, which are called “planing”. Such swimming equipment is designed to develop a speed not exceeding 60 km/h. Occasionally, water cannons can still be installed on medium-sized motor vessels, the angle of inclination of the bottom part of which does not exceed 20 degrees.

When installing, it is worth taking into account the weight of the engine, since the presence of water flows inside the equipment also increases the weight of the vessel. Compliance with such important calculations will extend the life of the engine.

However, despite the presence of additional mass, it is worth accepting the positive side of the water cannon. In this case, the absence of a heavy gearbox is a huge advantage. Its function is performed by a reverse steering mechanism.

During installation, experts recommend equipping the area between the water jet and the engine with a special (connecting) coupling. This will ensure isolation of the functioning motor, without taking into account the operating mode of the jet engine.

Motor attachments

Attachments for water jets are devices that allow you to convert an ordinary motor (outboard) into a water cannon in a few hours. The nozzles resemble centrifugal pumps, which, using impellers (impellers) through the water intake, draw water flows into the propulsion part and push them out with pressure in the direction opposite to the boat.

The main advantages of nozzles for water jets are:

• The ability to connect reverse at full speed, which gives a fairly powerful braking effect.
• The device is not equipped with switches in the gear section, which does not lead to rapid wear of the motor.
• Easy maintenance.

It is very important to syringe every 9-10 hours with a specialized lubricant (waterproof).

The disadvantages of motor attachments include:

• Reduction in power indicators by almost a third.
• High cost of parts, which is especially important during periods of repair work.

Jet motor for PVC boat

Assembling a homemade motor for a PVC boat is no more difficult than for other types of boats, but on the contrary, it is somewhat simpler. This is due to the fact that any outboard motors with a power of 15 to 20 horses are suitable for this. In addition, purchasing such outboard motors is not problematic, and their reliability is quite high.

You should also pay attention to the wide range of similar products, which allows you to choose the appropriate option.

At the same time, attention should be paid to models with the lowest weight, which is especially important. In this regard, preference should be given to imported models, although similar outboard motors are also produced by domestic manufacturers. At the same time, it’s no secret that domestic models are not as reliable as foreign ones

In addition, they are characterized by quieter and more economical operation.

At the same time, it’s no secret that domestic models are not as reliable as foreign ones. In addition, they are characterized by quieter and more economical operation.

To build a jet engine for a PVC boat, you should purchase the following components:

• Outboard boat motor.
• Special gearbox.
• Special flange.
• Hub.
• Welding machine.
• Development of the water collector.
• Engine drawing.
• Fittings.
• Waterproof glue.

The technology for converting a regular boat motor into a water jet engine is the same as for making a water jet for a regular boat.

Preparatory procedures

This is a very important stage in creating a water jet for a PVC boat, since its operational capabilities will depend on correct actions. At the same time, you need to take into account such things as the availability of special tools, as well as the availability of materials that meet the stated technical characteristics.

As a rule, such work is not considered particularly difficult and almost any boat owner can handle it if they wish.

Manufacturing process

As a rule, the inlet part of the pipe should be 1.5 times larger in diameter than the conduit itself. When crossing very shallow areas, 0.1-0.15 meters deep, rare tremors are possible, which indicates an insufficient amount of water entering the water cannon. It is at this moment that it can clog. This is due to the fact that in particularly small areas the pipe can capture silt or sand, along with the presence of other objects. To prevent this from happening, it is necessary to provide an input filter.

In order for the structure to work properly, it is advisable to manufacture it according to the drawings. Finding them will not be difficult, especially if you have the Internet. Although options with unfinished drawings are possible. That is, there are possible drawings according to which the water cannons were not manufactured and their performance was not tested. Such work requires special tools and special skills in working with materials and tools.

The water jet for a PVC boat operates in a normal transition mode, capable of bringing the boat to planing at a speed of 13-17 km/h. The efficiency factor (COP) of such structures is no less than 50%, which is quite acceptable and something that the classic type of outboard motor cannot boast of.

Blitz tips

• Efficient use on small vessels (with a carrying capacity of no more than 270 kg).
• Water cannons can be used in any weather and in any area of ​​the reservoir. The presence of vegetation and small debris does not interfere with the operation of the device at all.
• Water jets can be installed on watercraft with soft and hard bases.
• The efficiency of the motor has been experimentally proven both in deep-water areas of the reservoir and in shallow waters.
• The presence of strong gusty wind does not at all contribute to the difficulty of the engine.

DIY making

To achieve their goals, self-taught designers can be helped in many ways by numerous forums and sites on the World Wide Web, but theory is only half the battle; it also requires minimal skill in handling plumbing tools.
When manufacturing a suspended water-jet attachment, the best material is stainless steel sheet ; in some cases, pipes of different diameters are used; the individual parts are connected using electric welding.

Therefore, for enthusiastic designers, the ability to use an electric welding machine and special electrodes is a prerequisite for success.

In fact, a water cannon, as already mentioned, is a pipe, which is why, before starting work, a paper model is made, glued, tried on, and reinforced using the papier-mâché method with one or two layers of paper. Afterwards, a pattern is cut and made, transferred to metal, and the final form of the unit is formed, after which the resulting structure is welded, ground, and tested.

The suspended water jet is installed on the boat so that the intake hole is 2-3 centimeters below the level of the transom along the keel of the boat. On rubber boats with a water channel, the intake neck is installed at the level of the channel at the transom of the boat.

If the height of the standard transom of the boat is insufficient, then they resort to building it up; this is done by installing an additional structure using brackets, or permanently with a bolted connection.

For rubber boats today it is possible to order a ready-made removable transom, specifically designed for water-jet propulsion.