The situation when boat-engine It refuses to start at the most inopportune moment, can spoil the mood of any boating. Instead of enjoying fishing or cruising on the water, the owner finds himself on the shore with broken equipment, trying to figure out what went wrong. Most often the problem lies in one of three basic systems: fuel supply, sparking or compression. However, the devil is usually in the details, and ignoring the little things can lead to serious repairs.
Before panicking and calling a tow truck or service, it is worth conducting a primary medical examination. diagnostics In many cases, the reason is trivial, from old fuel in the tank to candles filled with oil. two-stroke or four-stroke The engine will help to quickly localize the malfunction, and in this article we will discuss the main failure scenarios and how to fix them.
If your engine slug-in After winter downtime, it can be the result of improper preservation, so let's figure out how to bring the technology back to life and avoid mistakes that can be costly.
Problems with the fuel system: the first line of defense
The most common reason why engine It's not going to start, it's about quality and fuel delivery. Gasoline tends to age, and if you leave a full-tank engine in storage without a stabilizer, next season you'll get a viscous substance that clogs the carburetor. Modern environmental standards make the fuel even more sensitive to storage conditions.
Pay attention to the state of affairs. fuel-filterIf it's filled with water or garbage, you can't get gasoline into the carburetor, and the water is heavier than gasoline, and it always accumulates down there, and it gets into the system first, and this is especially true for outboard motors, where the risk of condensation entering the tank is high.
⚠️ Warning: Never try to start a motor if you smell a persistent smell of gasoline in the area of lower unit, which may indicate a fuel leak, which poses a risk of fire if a spark appears.
Check the fuel pump. Many models have membrane pumps, and they're driven by crankcase pulsations, and if the pump's aperture is choked or broken, the fuel just won't make it to the pump. carburetorIt's also worth checking the tightness of the fuel hoses: cracks on them lead to air suction and impaired mixing.
Ignition system: search for sparks and diagnosis of candles
If the fuel is in order, the next step is to check the ignition system. Ignition candle It's an indicator of engine health. Turn it out and look at the carbon. Black, dry soda is a rich mixture, and white or melted electrode is a hot or poor mixture. Ideally, the color should be brick and brown.
The spark is checked by placing a candle on the engine mass. However, modern electronic ignition systems (CDIs) may not produce a visible spark in the air, as the breakdown requires less voltage than in a pressure cylinder. So having a spark "on weight" is not always a guarantee of serviceability, but its absence is a hundred percent sign of a problem.
- 🔌 Candle cap: Make sure it sits tight and there are no oxides inside, and often the problem is solved by simply cleaning the contact.
- ⚡ High-voltage wire: Check the insulation for cracks. The breakdown may go through the candle body or through a crack in the insulation, especially in wet weather.
- 🛑 The emergency stop sensor (Kill Switch): A banal, but frequent mistake is a forgotten emergency switch in the stop position or an oxidized contact of the cable.
On electronically controlled motors, the ignition advance angle may be lost due to a malfunction of the throttle position sensors or the crankshaft. serviceport Self-adjustment without equipment can lead to detonation and destruction of the piston group.
Always have a set of new spark plugs that match your engine, which is an expendable material that can save a situation away from civilization.
Air system and carburetor: balance of mixture
Fuel needs air to burn properly. air-filter If you're filled with dirt, oil or insects, the engine will suffocate, especially in four-stroke engines, where a polluted filter creates a vacuum that affects the engine, and it's a mandatory procedure to clean or replace the filter element regularly.
In carburetor engines, jelly clogging is a common problem, and even a microscopic moiety trapped in the fuel tank can block the idle channel, so the engine only starts when the throttle is fully open, or it dies immediately after starting. carburettor compressed air.
System system blending The mechanical actuator of the valve can become sour or the cable can stretch, so that the valve does not close completely when cold start. Without the enriched mixture, it is almost impossible to start a cold engine.
Symptoms of improper regulation of the carburetor
If the engine dies when the gas is opened abruptly, the mixture is probably too poor. If there is black smoke coming out of the exhaust and there are dips during acceleration, the mixture is too rich.
Mechanical part: compression and state of the CNG
When there is fuel and spark, but the engine does not start, it is worth checking. compressionThe low cylinder pressure prevents the temperature required to ignite the mixture, the compressometer is used to measure through the candle hole, and the two-stroke motors are considered normal for 6 to 9 atmospheres, and the four-stroke motors are higher.
The reasons for the compression fall can be different: wear of piston rings, bullies on the cylinder mirror or damage to the crankshaft coils. In two-stroke engines, the coils play a critical role, because they keep the fuel-air mixture in the crankcase. If the odule lets air in, the mixture is sucked out, and the engine stops starting.
| A symptom. | Probable cause | Method of verification |
|---|---|---|
| The engine catches, but it doesn't start. | Low compression or overenrichment | Compression measurement, candle inspection |
| It starts and it dies. | Problems with the fuel pump or air suction | Fuel supply check, joint spraying |
| Hard to spin a starter. | Hydro-impact or wedge bearings | Visual examination, hand-wringing |
| Scrolling knock | Destruction of the shaft-piston group | Auscultation (listening) of the engine |
Hydraulic shock is a dangerous phenomenon when water enters the cylinder, which happens when you try to start the engine if it has been turned over or stored in water with the exhaust holes open. The water does not shrink, and trying to turn the crankshaft can lead to a failure of the rod or deformation of the block head.
☑️ Diagnostics of mechanics
Features of launching four-stroke and two-stroke engines
Launch algorithms two-stroke and four-stroke The engine has significant differences that need to be considered in the diagnosis: two-strokes are more sensitive to the quality of the fuel mixture and the state of the exhaust system, the nagar in the silencer can completely block the exhaust gases, and the engine will stall.
Four-stroke motors are equipped with an oil lubrication system in the crankcase, which adds another level of complexity. Low oil levels can activate the emergency stop sensor, and the electronic control unit (ECU) will prevent starting. Also in 4-strokes, there are often problems with the valve mechanism: wrong valve mechanism: heat-gaps This leads to a difficult start and loss of power.
The electric starter on four-stroke engines is more powerful and requires a proper battery. The weak battery charge may be enough to spark, but not enough to spin the crankshaft at the desired speed. In two-stroke engines, manual start (twitching the starter cord) requires a certain technique: a sharp jerk to create a spark.
⚠️ Warning: When using an electric starter, do not hold the power button for longer than 5-7 seconds. This can cause the starter to overheat and the battery to run deep.
Seasonal issues: launch after winter storage
If the outboard motor slug-in In the spring, the reason is almost always the wrong preparation for the winter, the residue of fuel in the float chamber of the carburetor evaporates, leaving a resinous plaque that clogs the jelly, and in four-stroke engines can oxidize oil that has lost its properties.
The moisture that enters the ignition system during the winter also makes itself felt. Condensation on the contacts of the interrupter or inside the ignition coil is able to completely block spark formation. Drying of nodes with warm air (for example, a dryer at minimum temperature) often helps to resuscitate the system.
Proper preservation for the winter is the key to an easy start in the spring. Be sure to drain the fuel from the carburetor and treat the cylinders with conservation oil.
The battery could lose charge or sulfate during the idle time. Even if the light bulbs are on, the initiation current may not be enough. Check the electrolyte density and the voltage under load. For lithium starters, it is important not to store them at negative temperatures without charging.
Frequently Asked Questions (FAQ)
Why does the engine start and immediately stop after releasing the suction?
The problem is probably the carburetor's idling system, the idling jiclair can be jammed or the extra air is sucked into the system through the intake manifold, and it's also worth checking the adjustment of the screw quality of the mixture.
Can I use AI-95 gasoline for an outboard motor?
Yes, but with reservations: Modern engines are adapted to high-octane fuel, but it is important to monitor the presence of alcohol in gasoline (ethanol), which can aggressively affect rubber seals and plastic carburetor older models, better use fresh gasoline with the octane number recommended by the manufacturer.
What to do if water gets into the cylinder?
Don't try to spin the starter! Unscrew the spark plugs and swivel the crankshaft (hand or starter) a few times to throw the water through the candle holes. Then pour some oil into the lubrication cylinders and dry the system. If there was a lot of water, it is advisable to replace the oil in the gearbox and crankcase (for 4T), as it could emulsify.
How often do I need to change the fuel filters?
The fuel filter-settler (separator) should be checked and discharged before each trip to the water. Paper filters fine cleaning is recommended to be changed once a season or every 100 hours, depending on the operating conditions and quality of the fuel being refueled.