Transportation of outboard motors (PLMs) is a process that is often controversial among small boat owners, especially when it comes to four-stroke models. four-stroke motors They have an oil-filled crankcase, similar to a car, which places serious restrictions on their position when moving on public roads. Incorrectly positioning the unit on the trailer or in the car body can lead to lubrication leakage, candle contamination and, in the worst case, to a hydraulic shock on subsequent start-up.
The main problem is the design of the lubrication and ventilation system of the crankcase. If you put the motor on the side where the valves or sapons are located, the oil inevitably flows where it should not be. Many beginners make the mistake of thinking that a short trip of 10-15 kilometers will not cause harm, but even a slight tilt can cause oil to enter the cylinders through the system. PCV Not only is it environmentally harmful, it's also technically dangerous. combustion engine.
In this article, we will discuss the physics of the process, determine the only correct side for laying and consider the algorithm for preparing equipment for the long journey. Understanding these nuances will prolong the life of your equipment and save you from expensive repairs in the service center. Security The safety of the assemblies is the number one priority for any boat owner.
Design features of four-stroke engines
To understand the logic of transportation, you have to look inside the structure. A four-stroke motor has a closed lubrication system where the oil is in the pallet of the crankcase. When the engine is running, the pump circulates fluid through the channels, lubricating the rubbing vapors. However, in a static position, when the motor is turned off and tilted, gravity causes the oil to flow to the lowest point.
A critical element is the system. air-inlet There are valves in the cylinder head that close the combustion chamber, but there are always microscopic gaps between the valve rods and the guides, and if you put the motor on its side so that the oil rises above the valve level, it will slowly seep into the combustion chamber.
In addition, modern environmental installations of crankcase gas capture systems. sapoonThe sluice that connects the crankcase to the intake manifold, when strongly tilted, can become a channel through which oil mist or liquid itself enters the intake tract. spark-plug and smoke at launch.
⚠️ Warning: Attempting to start a motor that has oil in its cylinders when transported improperly can result in a hydraulic shock, the fluid does not shrink, and the shaky piston group can suffer fatal damage.
And it's important to consider the design of the diewood, and at the bottom of the gearbox, which also contains oil, but it's already transmission, and although it's more viscosity, long-term transport upside down or on the side can cause it to leak out through the propeller shaft coils if they're worn out or not designed to be so high.
The critical question: on which side is the laying allowed
The answer to the main question is unequivocal: a four-stroke outboard motor can only be carried on one particular side. Yamaha, Honda, Tohatsu and SuzukiIn their instructions, they indicate that laying is possible only on the left side (if you look at the engine from the rear, from the side of the pump or the gas traction).
Why left side? Most PLMs are designed to have exhaust holes and attachment points on the left side, and important lubrication and electrical components on the right side, and when you put it on the left side, the oil in the crankcase stays in the pallet, without reaching the level of the valves and piston rings.
Starboard stowage is strictly prohibited, where the oil from the crankcase flows instantly to the valve cover, and even if the engine does not start immediately, the first time you start, the oil will be thrown into the exhaust system, creating thick white smoke and contaminating the catalyst (if any) or silencer.
There is also a myth that the motor can be driven "upside down" (dadewood up), although this theoretically prevents oil from flowing out of the crankcase down to the valves, this method creates excessive pressure on the engine. squirrel And also, there may be a vacuum or an overpressure in the lower unit, which will damage the propeller shaft seals.
Algorithm of preparing the motor for transportation
Even if you know the right side, you can't just put the engine down and drive. It takes a few minutes to prepare, but it saves you from problems. The first step is always to drain the water from the cooling system. After you use it, you have water in the lower unit and pump, which when mixed with oil or when you freeze (in winter) corrosion.
The second important step is to fix the hummel or the remote control thrust, and if the motor is rumble-controlled, it needs to be secured in the transport position so that it doesn't hang around, and for remote models, you need to make sure that the cables are not twisted and will not be stretched when laid down.
☑️ Checklist of preparation of outboard motor to the road
Step three is cleaning. Wash the salt and dirt off the outside before packaging. Aggressive sea salt combined with moisture inside the cover during transportation can quickly corrosion aluminum alloys and steel bolts. Use fresh water and a soft brush.
Finally, check the fuel system. If you're planning a long stay, you'd better get the fuel out of the carburetor or close the tap. Gasoline has the ability to evaporate and leave a resinous sludge, and it can expand when heated, creating pressure in the mainline.
Comparison table: two-stroke vs four-stroke engines
Understanding the difference between engine types helps avoid confusion: Two-stroke engines are much more omnivorous in terms of transportation, since they lubricate with oil mixed with gasoline and have a dry crankcase (used for purges).
| Parameter | two-stroke motor | four-stroke engine |
|---|---|---|
| The presence of oil in the crankcase | No (mixture in the gas tank) | Yeah (separate pallet) |
| Side-line transportation | Allowable on either side | Only on the left side. |
| Risk of oil entering cylinder | Minimum | High (when placed on the right side) |
| Sensitivity to tilts | Low. | High. |
As you can see from the table, four-stroke It requires a lot more care. two-stroke may worry less about the position of the engine, but the owner of the four-stroke must observe strict discipline.
It is worth noting that there are exceptions for some low-power models (up to 2.5 hp), which may have specific design requirements. Always check the manual of a particular device, as engineering solutions may differ from one brand to another.
Typical errors in transport and their consequences
One of the most common mistakes is to tilt when starting after a ride, and if the engine is on the right side or flipped, you can't start it as it is, you have to let it stand upright for at least 30-60 minutes to get the oil glass back into the crankcase.
The second mistake is to use the wrong covers, and the fabric covers that fit the engine can create the thermos effect or, conversely, sail on the track, and it is better to use hard cofres or securely attach soft cases so that they do not rub against the lower unit.
What if the engine is already started after improper transportation?
If you notice a strong white smoke from the exhaust immediately after starting, immediately turn off the engine. Let the engine cool down and stand upright for several hours. When you start again, the smoke should disappear. If the smoke persists, perhaps oil has entered the muffler and it will have to be removed for cleaning.
The third mistake is the weak fixation on the trailer. The motor is a heavy pendulum. If it's not properly fixed, vibrations and jerks when driving on rough roads can cause the brackets to break or even detach from the lower unit. Use bracket straps, not simple rubber bands.
Fixing and fixation on trailer or body
Safety on the road depends on the quality of the mounting. The motor must be fixed not only in the horizontal plane (so as not to fall on the side), but also in the vertical plane (so as not to jump).
If the motor is removed from the boat, it is ideal to install it in an upright position in the car body, but it requires a reliable fixation of the base. If laying is inevitable, use wooden bars or special stands to create a support along the entire length of the lower unit and engine compartment.
Don't forget the wind load. At the speed of the track, even a small motor experiences significant air pressure, and the cover must be windproof or additionally covered with an awning so that the air flow does not try to disrupt the structure.
Seasonal storage and long-term conservation
The position of the motor is not only relevant for fishing trips, but also for winter storage. If you leave the motor in the garage for the winter, it is also better to store it in an upright position. Prolonged stay on the side can lead to deformation of the glands under the weight of the parts or uneven distribution of lubrication.
When preserved for more than a month, it is recommended to treat the internal cavities with an anti-corrosion spray (fog), which will create a protective film on the cylinder mirror and bearings. For four-stroke engines, it is also useful to replace oil before wintering, since the waste oil contains combustion products and acid, which can erode parts in prolonged downtime.
Long-term storage of the four-stroke engine is possible only in the vertical position, laying on the side is permissible only for short-term transportation and strictly on the left side.
Check the fuel system before the season. Gasoline left in a carburetor or injection ramp for six months becomes a viscous substance that can completely clog the jellyplants, use fuel stabilizers or completely drain it from the system.
Frequently Asked Questions (FAQ)
Can I transport a four-stroke engine upside down (dadewood up)?
Theoretically, this is possible because oil won't flow to the valves, but manufacturers don't recommend this method because of the risk of damage to the crankshaft glands and gaskets under the weight of the piston group and pressure in lower unit.
How long do you need to defend the engine after transporting on the side before starting?
The recommended time is 30 minutes to 1 hour in the upright position, which is necessary for oil that hits the top of the engine or carburetor to return the glass to the crankcase, starting earlier can lead to hydraulic shock or severe smoke.
Is a short trip (5km) on the right side dangerous?
Yes, it's dangerous. It doesn't take long for oil to flow through the valves under gravity. Even 5 kilometers on rough roads will create the conditions for mixing the oil with the fuel mixture or getting it into the cylinder. The risk does not justify the time saved for the transfer.
Do I need to drain the oil from the lower unit gearbox before transportation?
No, you don't need to drain transmission oil from the gearbox before every trip, it's designed to work in any position of the lower unit, but before long-term storage (winter) check the level and condition of the oil in the gearbox.
What if the engine smokes after improper transportation?
White smoke indicates oil burning. Turn off the engine, let it cool and stand upright for a few hours. If the smoke disappears when you start it again, the system self-cleanses. If the smoke is black or blue and doesn't pass, you need to diagnose candles and the piston group in the service.