The operation of an aluminum boat, or "Kazanka" as it is often called, opens up completely new horizons for the angler and tourist, but to turn the boat into a full-fledged high-speed boat, you need a competent installation of the outboard motor, errors at this stage can cost not only money for repairs, but also safety on the water.
The process of mounting a power plant on metal requires a special approach, different from working with PVC or plastic. Aluminum has a high thermal conductivity and a tendency to electrochemical corrosion when in contact with other metals, which dictates its conditions of fastener. sink-board It must withstand not only the weight of the engine, but also dynamic loads during planing.
In this article, we will take a look at all the steps from choosing the right mount to the final break-in, and learn how to avoid the common mistakes that 80% of beginners make when trying to save time or materials. Quality installation This is a guarantee that your boat will last for decades without leaks and distortions.
Selection and preparation of transcoat plate
The first step is to assess the condition of the translatum, the aft bulkhead on which the motor will be attached. If you plan to install it on an old boat, make sure that the metal does not have through corrosion and cracks. New boats or translatation often use stainless steel or aluminum cut-in translatum slabs, which greatly simplify the life of the owner.
The tray plate must be installed strictly vertically or with a small angle of inclination inside the cockpit (usually 10-15 degrees) to ensure the correct exit of the boat for sleeve. The wrong angle will lead to " yaw" with the nose or, conversely, to the burying of the boat in the wave. epoxy or sealant for additional fixation.
When choosing fasteners, give preference to stainless steel grade AISI 304 or AISI 316. Using conventional ferrous metal or galvanizing in salt water or even in fresh but aggressive environments, will lead to rapid corrosion. Remember that galvanic pair "aluminum-steel" requires mandatory insulation.
When installing a transom plate, use a pad made of paronite or special rubber between the metal of the plate and the boat hull, which will prevent direct contact of dissimilar metals and reduce the risk of electrochemical corrosion.
Marking and drilling of holes in the body
The most important and irreversible step is drilling holes in the aluminum board. There is no room for error here, because the extra hole is a potential leak and weakening of the structure. Before starting work, you need to carefully measure the distance between the fastening holes of the motor or the transom plate.
Use a corer to apply accurate marks. Aluminum drilling requires sharp metal drills and low drill rpms to keep the material from overheating. Overheated drills lick the edges of the hole, making it impossible to seal the hole in the future. cobalt-drillThey are less sloppy and give a clean cut.
⚠️ Attention: Before drilling, be sure to remove the inner lining or access to the back of the side. You should see where the drill goes so as not to damage the internal structural elements or wiring if it is already laid.
The holes must be in a very close diameter to the bolts, and if the holes are too large, the bolts will hang around, and the sealant will not be able to do its job, and if they are too small, the metal can deform when tightened, causing microcracks around the fixture to form.
☑️ Drilling tools
Sealing of fasteners
The issue of sealing in aluminum boats is particularly acute. Unlike fiberglass, aluminum has a high coefficient of thermal expansion, so conventional silicone sealants can detach over time. To install the engine, you need to use specialized polyurethane or MS-polymer sealants that have high metal adhesion and elasticity.
The sealant process requires surface cleanliness. The metal around the holes must be degreased with acetone or alcohol. The sealant is applied not only to the bolt thread, but also to the adjacent area around the hole. The bolt is inserted into the hole filled with sealant, creating a "cork" effect, which, when dry, becomes a monolith with the body.
Pay special attention nut-breakingThe vibration of the running motor can unwind even a tight nut. Use grover washers (spring washers) or self-contradicting nuts with a nylon insert. This is a critical safety element.
Why can’t you use acid silicone?
Acid silicone, when dried, releases acetic acid, which causes severe corrosion of non-ferrous metals, including aluminum. This will destroy the fastener and the housing around the hole in one season. Use only neutral sealants labeled "metal" or "boat"
Installation of lower unit and adjustment of the angle of inclination
Once the slate is securely secured, it's the turn of the engine itself, and it's important to set the right angle of the diewood, adjust it with a strap (holes in the motor's bracket), and adjust it correctly for speed, fuel consumption and handling.
If the lower unit is too deep, the boat's nose will swell and the water's resistance will increase. If the anti-cavitation plate (the flat part of the lower unit above the screw) is too high, the screw will start to grab air on turns, losing traction. The ideal situation is when the anti-cavitation plate goes parallel to the bottom of the boat or with a slight tilt down when driving at full speed.
| Setup parameter | Symptom of error | Decision |
|---|---|---|
| The engine's too low. | Boat "scouring", high fuel consumption | Raise the engine one hole higher |
| The engine's too high. | The screw grabs air, loss of traction. | Lower the engine. |
| Wrong trim | Boat's not going to planing. | Adjustment of the inclination angle by the seal |
Remember to check the cooling system immediately after installation. The outgoing water stream ("control") should be powerful and smooth. Lack of water in the jet even for a few seconds can lead to overheating and jamming of the piston group.
The golden rule of tuning: the anti-cavitation plate should be 3-5 cm below the bottom of the boat in a static position for most aluminum boats 3-5 meters long.
Connection of steering and cables
Mechanical steering requires the right cable laying. The cable should not have sharp curves, the bend radius should be at least 30 cm, otherwise the inner shell will quickly collapse and the control will become tight.
For gas cables and gearshifts (reverse), it is also important to ensure free running. The tension of the cable should be such that the levers on the motor move to the end without jerking, but also without backlash. Use plastic clamps or special clips to fix the cables to the sides, eliminating their friction against the sharp edges of aluminum.
When laying electrical wires for remote control (if the motor is electric starter), use only copper wires in double insulation. The wires must correspond to the starter's current consumption, otherwise voltage loss and failure of start may occur. All connections must be soldered and protected by thermal shrinkage.
⚠️ Attention: Never put a fuel hose and electrical wires in the same harness or cable channel without separation. In the case of sparking or short circuit, this can lead to the ignition of gasoline vapors.
First launch and break-in
After all the installation work is done, the moment of truth comes, the first start. Don't rush to full gas at once. Let the engine warm up at idle speed for 5-10 minutes. Listen carefully to the engine's operation: there should be no foreign knocks, vibrations or whistles.
The first hours of operation (usually 10 hours or 2 tanks of fuel) are considered break-in. During this period, you can not exceed 50-60% of the maximum power. boat-engine At times.
During the first exits, be sure to check the condition of the mounting bolts of the transom plate. After vibration loads, they may weaken slightly and need to be tightened. Also check the sealing sites for leakage.
How to check the thermostat at the first start?
Put the engine in a tank of water or shallow water. Start the engine. In 2-3 minutes, touch the body of the lower unit in the area of the outlet, it should become warm, indicating the opening of the thermostat and the circulation of coolant in a large circle.
Frequently Asked Questions (FAQ)
Do I need to lubricate the motor mount bolts before installation?
Yes, it is. The bolts should be lubricated with graphite or anticort before being screwed in, so that the bolts will not stick to the aluminum and will make it easy to dismantle the motor in the future, but you need to apply a sealant on the bolt head and the washer.
Can I use wooden pads for an outboard motor?
Using wood as the main gasket for the aluminum engine is not recommended, since the wood absorbs moisture and rots, creating a focus of corrosion. It is better to use special rubber shock absorbers or plastic spacers if plane alignment is required.
Which sealant is better for aluminum in water?
Polyurethane sealants (e.g. Sikaflex 291i or similar) are best known for their high adhesion, ultraviolet light, and elasticity at temperature extremes, which is critical for aluminum.
What if after installing the motor, the boat takes you to the side?
Most likely, the twist angle of the lower unit (trim tab) is incorrectly exposed, or the lower unit itself is skewed relative to the diametrical plane. Try adjusting the small fin ( yaw compensator) under the anti-cavitational plate, turning it in the opposite direction of the lead.