The dream of every owner of an inflatable boat or a small boat is to have a spare, easy and cheap way to travel on water, which does not require registration with the GIMS and complex maintenance. trimmerThis is an engineering solution that attracts anglers and tourists because it's affordable, because the trimmer itself and the attachment are much less expensive than the specialized outboard motors.
However, do not think that the process is simple and devoid of nuances. Water-gun nozzle It has its own power limitations, requires proper alignment and safety regulations, ignoring which can lead to engine failure or water accidents. In this article, we will discuss in detail how these devices work, conduct a comparative analysis of popular models and give step-by-step installation instructions.
It should be noted that this device is not a toy for high-speed walks, its lot is the quiet movement of a fisherman with gear or a tourist with cargo on board. Water-guideThe thrust, which is the basis of the design, provides traction by ejecting a jet of water, which makes it safe to swim next to the boat, but reduces the overall efficiency compared to propellers. Let's dive into the details so you can make an informed decision about buying.
Principle of operation and design of water jet nozzle
The basis of the device is water-pumpIt's a tube with an impeller inside, which is mounted to the trimmer bar instead of a cutting assembly, and it's basically a tube with a shaft that is driven by a shaft that is connected to the trimmer motor through a gearbox or directly, and it's sucked in through the inlet underneath the boat, and it's thrown out forcefully through the nozzle in the aft, creating jet thrust.
The key element here is tightness Because the engine is above water and the working part is submerged, any leak can cause water to enter the exhaust system or trimmer gearbox, which can cause hydraulic shock, so manufacturers use a multi-stage sealing system and ossicles that require periodic inspection.
⚠️ Attention: Never run a trimmer with a nozzle out of water, even for a few seconds. The lack of cooling water instantly overheats the lower unit pipe and can warp seals, leading to costly repairs.
Control is performed by rotating the entire structure around the vertical axis (to change course) and adjusting the speed of the trimmer engine (to change speed). tiller with a reverse valve cable, allowing you to reverse, which is critical for maneuvering in narrowness.
Technical nuances of the impeller
The impeller in water jet nozzles usually has a smaller step than in full-fledged jet drives to match the high revs of the two-stroke trimmer engine. This creates high pressure, but limits the water throughput, making the system sensitive to large debris and algae.
Advantages and disadvantages of using a trimmer on water
The main advantage of such a system is universalityYou buy one engine that cuts grass in the summer and turns into a outboard motor on the weekend, and it's the perfect solution for those who don't want to store the second engine, change the oil in two devices and pay for extra equipment, and it's also a minimal weight set, which is important for hiking to water bodies.
But the medal has a downside. Noise A two-stroke trimmer engine located directly overhead can be tedious for long transitions, and it is also worth considering the vibration that is transmitted to the transom of the boat and requires high-quality fixation so as not to damage the inflatable vessel side.
- 🚤 Economics: Fuel consumption of a trimmer with a volume of 30-50 cubic cm is much lower than that of a full-fledged outboard motor of the same power, which allows you to take less gasoline on the hike.
- 🔧 Repairability: Trimmer engines are common everywhere, spare parts are cheap, and the design is familiar to many craftsmen, unlike specific outboard motors.
- 🌊 Safety: The absence of external rotating screws makes the nozzle safe for people and animals who accidentally found themselves overboard.
And we must not forget that resource The trimmer is often operated in full load mode, especially when driving against the current or wind, and this can lead to accelerated wear of the piston group if the temperature is not observed and the engine is not allowed to cool down.
Use a mixture of gasoline and oil with a slightly higher oil content (e.g. 1:40 instead of 1:50) if your trimmer works in tension on the water for a long time. This will improve lubrication and reduce the risk of overheating, although it will increase the soak on the candle.
Overview of popular nozzle models
The market offers several adapter options, differing in the way of attachment, housing material and compatibility with trimmer brands. aluminum-alloy Plastic versions are cheaper and lighter, but more prone to wear and tear from sand and stones.
Special attention should be paid to the mounting system to the barbell. There are universal clamps suitable for most models. Husqvarna, Stihl and ChampionIt is important that the diameter of the pipe coincides with the landing site of the nozzle, otherwise there will be backlashes or distortions.
>Compatible engine volume (cc)
| Model nozzle. | Case material | Features | |
|---|---|---|---|
| WaterSnake Pro | aluminum | 33 - 52 | Enhanced lower unit, the possibility of installing an electric starter |
| Fisherman-1 | Reinforced plastic | 25 - 40 | Lightest model, ideal for small PVC boats |
| JetBoat Universal | Stainless steel | 40 - 60 | Maximum durability, reversible valve included |
| EcoWater Mini | Plastic/Aluminium | 20 - 35 | Budget option, requires accurate alignment of the shaft |
When choosing a model, pay attention to the availability anticavitationalIt's a flat element above the nozzle, which prevents air from being captured from the surface of the water, which is especially true in shallow water, and the absence of such a plate will cause the flow to break down and the thrust to lose at the slightest wave.
Step-by-step instructions for installation and configuration
The installation process requires care and precision, first you have to remove the cutting headset from the trimmer, then you put the nozzle on the shaft, which is fixed by the clamps, and it's critical to ensure that the trimmer shaft and the nozzle shaft are aligned to avoid beating and breaking the bearings.
Then there's the step of attaching the whole structure to the trunk of the boat, and this is done using a special bracket or a rod that's included in the kit. Height of installation adjustable so that the water intake hole was completely submerged, but the nozzle itself did not create excessive resistance when moving.
☑️ Check before the first launch
After the physical installation, you need to check the system for vibrations, start the engine at idle speeds, while on the shore or in shallow water (caution!), and inspect the connections. If you hear a foreign knock or feel a strong vibration on the handles, the installation should be repeated, paying attention to the connection. centre.
⚠️ Attention: Before the first full swim, be sure to check whether water enters through the control hole (if it is provided by the design) or whether the flow of water is felt at the exit. Working "dry" even for 10-15 seconds can cause seals to fail.
Operation and safety measures on water
The trimmer boat has its own specifics, and because it has no gearbox and no neutral gear (in basic configurations), it stops by dropping gas, which means that the boat continues to move inertia. For an emergency stop, you need to shut down the engine, which is not always convenient in a dynamic situation.
When driving, avoid areas with abundant vegetation and bottom debris. Although the jet drive is less sensitive to grass than the screw, long algae can wind on the shaft and block it, causing overheating, in which cases immediate stop and cleaning is required.
- 🛡️ Protection against rollover: Always use a safety cable (check), if it is provided by the design of the mount, so that when a sharp jerk the trimmer does not fly into the water along with the boat.
- ⛽ Fuel control: Have a fuel supply, as trimmers consume the mixture faster at full speeds, and it is extremely difficult to swim on oars with a heavy nozzle installed.
- 👓 Remedies: Be sure to use a life jacket and safety goggles, as the spray from the transom may contain sand and small stones.
It's important to remember wind-loadLightweight inflatable boats with sailing and low-power trimmer can become unmanageable in strong lateral winds, in such conditions it is better to refuse to get on the water or stay closer to shore.
The main rule of operation is not to boost the engine. Trimmer is not designed for long-term operation in full load mode, like a specialized outboard motor, so keep your speed at 80-90% of the maximum.
Maintenance and storage
After each release, the device requires a freshwater wash, salt water or algal water aggressively affects metal and rubber seals, and you flush the system by lowering the water intake into a container of clean water and letting the engine work for a couple of minutes.
Check your condition regularly sludge The appearance of backlash or noise when the shaft is rotating indicates the need to replace these elements, and ignoring this requirement can lead to jamming of the shaft and breakage of the trimmer engine.
When stored in the off-season, the nozzle must be completely disassembled, lubricated with a consistent lubrication of all metal parts and stored in a dry place. The trimmer itself also requires conservation: draining fuel, cleaning from soak and lubricating the cylinder.
How often should you change the oil in the gearbox?
If your model of nozzle has a separate gearbox (usually aluminum versions), it should be replaced every 50 hours or at the end of the season. Use a special transmission oil for water equipment, which is not afraid of emulsifying when water enters.
Can I use a nozzle on a four-stroke trimmer?
Theoretically, yes, if the shafts and the revolutions are the same. However, four-stroke trimmers are heavier and have a different torque curve, which can reduce the efficiency of the jet drive. In addition, the angle of inclination of the engine when operating on water can disrupt the four-stroke lubrication system if it does not have a pressure lubrication system.
What is the maximum speed of a boat with such a nozzle?
With a trimmer of 1-1.5 hp, speeds rarely exceed 5-7 km/h on a light PVC boat. This is pedestrian speed, but with no rowing. For high-speed walks, this solution is not suitable, its target audience is fishermen and lovers of quiet walks.
The durability of your system depends on the quality of the wash after each use, and the residues of salt and silt are the main enemies of the bearing nozzle.
In conclusion, the trimmer nozzle for a boat is a compromise, but functional solution for tasks: it will not replace a full-fledged engine for serious travel, but it will be an excellent assistant for short swims and fishing on the nearest lake. With proper operation and compliance with safety measures, this device will last for many years.