Torsion of the outboard motor: diagnosis and treatment

Any experienced boater knows that the smooth hum of an engine is music, but when the engine starts to "trick", twitch or stall on idles, pleasant moments on the water end. In boat owners, this phenomenon is often called "twisting", although it is technically more competent to talk about skipping ignition or uneven cylinders. A situation where one of four cycles works improperly creates imbalance, vibration and loss of power, which on the water can be not only unpleasant, but dangerous.

Symptoms fault They can be different, from a slight twitch of the hummel to a complete failure of the engine under load. Often beginners confuse the real problems with the settings of the fuel mixture or the quality of the gasoline. Tohatsu or Yamaha It's a strange thing to do, and you can't ignore it, and the long run of the engine, with the misfire, it causes the engine to overheat, flush the grease out of the cylinder, and eventually, it can be expensive to overhaul.

In this article, we will discuss the mechanics of the process, the causes of torsion and how to fix it yourself, you will learn how to distinguish a candle problem from a switch malfunction, why compression is important and how to properly configure the carburetor. It is critically important to understand that 80% of cases of “torsion” on two-stroke engines are associated with the ignition system and the quality of the spark, and not with the piston group. Do not rush to disassemble the engine, start with a competent diagnosis.

⚠️ Warning: Before starting any work with the fuel system or electrical equipment, be sure to disconnect the emergency stop motor (kill switch) and remove the caps from the candles. The rotating flywheel and high voltage pose a real threat to life.

The mechanics of torsion: what happens inside the engine

To understand the problem, we need to briefly recall the principle of the two-stroke engine: a mixture of fuel, oil and air is compressed, ignited by a spark, pushes the piston, and then pushed through the exhaust window. Torsion It occurs when this cycle is disrupted in one of the cylinders, and the mixture either doesn't ignite at all, or doesn't burn completely, or burns too soon or too late.

As a result, the piston gets less power to push than its neighbors in multi-cylinder engines, or doesn't get it at all, which causes the crankshaft to experience uneven loading. Instead of smooth rotation, we get jerks. This is perceived as "sneezing" or sneezing into the muffler. Vibration is transmitted to the lower unit and the trunk of the boat.

The particular danger is that the engine is running in this load mode when you're trying to get the boat to plane, and the engine can just choke and stall, leaving you stranded, and in the worst case, if the mixture continues to flow into the idle cylinder, it flushes the oil film from the walls, causing dry friction and bullies.

Often drivers fail to notice the first signs, writing off the vibration to the screw or the condition of the transom, but if you feel that the motor is not pulling or is not operating stable on idles, this is the first bell.

Ignition system: candles, coils and switches

The most common cause of torsion is problems with spark formation. Water and vibration are the main enemies of the outboard motor electrician. The first thing to do when symptoms appear is to check. spark-plugTheir state can tell us a lot about the processes that go on inside the cylinder.

Turn the candles out and inspect them carefully. The color of the insulator should be brick brown. If the candle is black and wet, the mixture is too rich or there are problems with the spark. If the white one is poor, which threatens to overheat. The gap between the electrodes should be according to the manufacturer's specification, usually 0.8-1.0 mm for most two-strokes.

• 🔥 Nagar: Soft black soda indicates a rich mixture or an incorrect ratio of oil in gasoline. Hard black soot is a sign of poor combustion or skipping a spark.
• 💧 Oil: If the candle is all in the oil, perhaps worn piston rings or oil caps (on four-strokes), or the proportion of the mixture is broken.
• ⚡ Spark: Check for a spark by pressing the candle skirt to the engine mass. The spark should be bright, blue and stable. A weak orange spark is a sign of a malfunction of the coil or switch.

And high-voltage wires, too. In constant humidity, the insulation can crack, and the current can start to break through, especially in rain. Also check the reliability of the engine's mass contact. Oxidation of the contacts on the stator or poor grounding often causes unstable operation. CDI module.

Fuel system: carburetor and quality of mixture

If the electrics are in order, the next candidate for testing is the fuel system. carburetor It's the heart of the engine, where the combustible mixture is made, and the slightest bit of jelly, the fuel level in the float chamber, or the air pump can cause trifling.

Often the problem lies in poor quality gasoline or the wrong mixture with oil. Old gasoline loses its properties, it falls out of resins that clog the thin channels of the carburetor. Water in the tank is another frequent guest, especially when refueling in the rain or storing a boat outside. Water is heavier than gasoline and accumulates at the bottom of the tank, getting into the engine at the most inopportune moment.

The symptoms of fuel starvation or re-enrichment are similar to ignition problems, but there are nuances: If the engine "troit" only at high speeds, most likely, there is not enough fuel (the main jikler or fuel filter is clogged), if the problem is only idle, it is the fault of the idle jikler or the quality of the mixture adjustment screw.

The sequence of the fuel system inspection:
1. drain the old petrol from the tank.
Check the fuel filter-settlement for the presence of water.
3. Blow the fuel hoses and pear.
4 Remove and wash the carburetor (especially jelly).
5. Check the leakproofness of the intake manifold.

It's also important to check the condition of the crankshaft glands, and if the oedle from the exhaust side or under the flywheel blows or wears out, it starts sucking air, and the excess air depletes the mixture in a particular cylinder, causing torsion, and you can check this by spraying WD-40 on the joints of the running engine: if the speed changes, the tightness is broken.

Compression and condition of the piston group

When the electrics and fuel are in order, it remains to check the "health" of the engine itself. Compression This is the pressure that the piston creates when it compresses the mixture, so if the compression is low, the mixture will not be able to ignite normally, and the cylinder will stop working.

Measurement requires a compressometer with a threaded tip that fits your engine candles (usually 14 mm). Unscrew all the candles, swivel the device into the opening of the first cylinder and sharply turn the starter (or pull the starter handle) several times. Write down the readings. Repeat the procedure for all cylinders.

Motor condition	Compression (kg/cm2)	Dispersion between cylinders	Diagnosis.
New engine	9.0 – 11.0	less than 0.5	Norma.
B/W (good)	7.0 – 9.0	less than 1.0	Working status
Requires repairs.	5.0 – 7.0	1.5	Wear of rings/cylinder
Critical	less than 5.0	anyone	Premium is required

If one cylinder has a much lower compression than the others, this is the cause of torsion, and the reasons can be different: stale or broken piston rings, bullies on the cylinder mirror, a burn of the piston or loose fit of petal valves (petals) in the intake manifold.

Sometimes low compression is caused not by mechanical wear, but by soot. Solid deposits can get stuck in the grooves of the rings, preventing them from fitting tightly against the walls. In such cases, decoking helps, but on outboard motors, this method does not always work effectively because of the design of the purge windows.

⚠️ Attention: If you find that the compression has dropped to zero after measuring it, it may be that the piston has jammed or broken. Do not try to start such a motor, it will lead to the collapse of the crankcase.

Carburetor adjustment and adjustment XX

Often, motor owners, trying to get rid of the unstable work, start to twist the carburetor's adjusting screws without understanding the process. idle and the quality of the mixture is a fine adjustment that must be carried out on a warmed-up engine.

Most outboard motors have two main carburetor screws: a quantity screw (rests with the valve) and a mixture quality screw. A quality screw regulates the air supply at low speeds. By twisting it, we enrich the mixture, twisting it, we impoverish it. The task is to find the middle ground at which the engine works as smoothly as possible.

The adjustment algorithm is simple, but it requires precision. Warm up the engine to operating temperature. Start slowly twisting the mix quality screw until the speed starts to fall and the engine starts to stall. Then smoothly twist the screw back until the speed increases and the work stabilizes. If the engine then stalls on idle, add a few turns with the number screw.

The secret to stable idling

Often the problem is not the screws, but the air pump through the gasket between the carburetor and the engine. Try spraying the carburetor cleaner around the intake manifold on the running motor. If the revs hop, change the gasket.

Remember that on electronically controlled two-stroke motors (e.g., E-TEC or OptiMax), the mechanical adjustment of the carburetor may be absent or limited. In such cases, torsion is often treated with a reflash of the control unit or replacement of nozzles / NTVD.

Prevention and useful tips of water motors

The best treatment is prevention. Mercury, Suzuki Or any other person who has been in service for a long time and doesn't know what torsion is, follow simple rules of operation: change fuel filters regularly, use only quality gasoline with the right octane number and special oil for water engineering (TC-W3).

After each operation, especially in salt water, be sure to wash the cooling system with fresh water. Corrosion can damage not only lower unit, but also the electrical contacts inside the stator. It is also useful to take off candles once a season and visually evaluate the color of the soda - this is the best indicator of engine health.

• 🛢️ Conservation: If you're putting the boat away for the winter, be sure to mothball the engine. Pour the gasoline out of the carburetor or add a fuel stabilizer to avoid tar formation.
• 🔧 Pimp: Once a year, check the tightening of the carburettor, intake manifold and exhaust bolts. Vibration weakens the connections.
• 🧹 Cleanliness: Keep the under-hood clean, and the dirt and oil that sticks to the engine interferes with cooling and hides leaks.

Remember, paying attention to minor engine failures in a timely manner can save you from costly repairs in high season.

Frequently Asked Questions (FAQ)

Can it be caused by bad oil?

Yes, the use of inappropriate oil (for example, for air cooling) or a violation of the proportion of the mixture (too much or little oil) leads to the formation of soot, which disrupts the sparking and operation of the valves, causing triplication.

Why does the engine only work on cold?

This often indicates problems with the mix enrichment system at start-up (if it is automatic) or the presence of condensate/water in the fuel system, and the wear of the glands, which allow air to pass through cold air, and expand and compact when heated, is also possible.

How to distinguish a torsion from a screw problem?

If the motor is idling (in gear or neutral, depending on the type of motor) and the vibration is coming from the engine, it is torsion. If the motor is running exactly on idles, but the shaking only occurs when you set speed, most likely the problem is the screw (crushed blades, cavitation) or lower unit.

Is it dangerous to operate a motor with torsion?

Short term -- yes, you can go ashore. Long-term use is dangerous: the cylinder that doesn't burn oil, it flushes the grease off the walls, leading to overheating of the piston, bullying and eventual engine jamming.