Solenoid sucking outboard motor: diagnosis and repair

Starting a cold outboard motor is always stressful for the mechanical components and nervous system of the owner of the boat. If the engine refuses to start or stalls immediately after start, 80 percent of the time the problem lies in the fuel-air mixture supply system. suckerThis automatically adjusts the enrichment of the mixture depending on the engine temperature.

Many aqueous motorists ignore this assembly until it finally fails, leaving them stranded at the most inopportune moment. Understanding the way this electromagnetic valve works allows you to quickly diagnose the problem on the water without having to resort to a service center. In this article, we will discuss the device, typical malfunctions and methods of restoring the cold start system.

Principle of operation and purpose of electromagnetic valve

Main objective solenoid Unlike the old carburetor models, where the driver had to pull the cable by hand, modern two-stroke and four-stroke motors use electric control. When you turn the ignition key on the starter, the solenoid coil is voltageed, the rods are retracted or extended, opening access to additional fuel.

The process is cyclical: when a cold engine is started, the valve is opened, providing a rich mixture. Once the motor starts to work and generate current through the stator coil (or through a separate generator circuit), the voltage on the solenoid changes or disappears, and the spring gradually closes the valve. This process usually takes from 30 seconds to 2 minutes, depending on the model of the motor. Yamaha or Tohatsu.

And it's important to understand that there are two windings inside the device, the trigger and the hold, and the one creates a powerful magnetic field to move the rod abruptly, and the other only keeps it in a working position with less energy consumption. sucker ceases to function correctly, which leads to either the inability to start, or to "choking" the engine with gasoline.

Typical symptoms of a solenoid malfunction

Diagnosis starts with observing the behavior of the engine, and if the outboard motor starts and immediately stops, or if it only runs at high speeds but does not keep idling, these are classic signs of a problem with enrichment of the mixture. Also worth listening to: a serviceable solenoid emits a characteristic click when the ignition is turned on.

Often drivers confuse the symptoms of a malfunctioning pump with problems in the ignition system or fuel quality. electromagnetic valveIf you notice that the engine smokes more than usual after starting or, conversely, shoots into the muffler due to the diluted mixture, you should pay attention to the rod and coil.

Let’s look at the main signs in more detail:

• 🔥 The engine starts only with a fully open throttle (gas), and on idle deafness.
• 🔥 There is no characteristic click when the ignition is activated in the "Start" position.
• 🔥 The engine runs unstable for the first minutes until it warms up, even in warm weather.
• 🔥 Visible damage to the insulation of the wires or traces of overheating on the body of the solenoid.

Visual examination and initial inspection

Before you pick up a multimeter, you need to do a thorough visual inspection. Often the cause is trivial: oxidized contacts, rubbed wire or mechanical jamming of a rod, remove the carburetor cover (or access to the pump assembly) and assess the condition of the unit. Mercury and Hidea access to the solenoid is usually open from the side of the carburetor.

Notice the rod. It has to move smoothly, without jamming. If the rod is open, the engine will choking. If it's closed, it will be extremely difficult to start a cold engine. In some cases, simple cleaning and lubrication of the mechanism helps, but if the rod is corrosive or the thread is damaged, you will need to replace the assembly.

⚠️ Attention! Before any inspection of the electrical part, be sure to disconnect the battery terminals. Short circuit in the wiring of the suction pump can cause fuses to burn out or damage to the stator coil.

Check the integrity of the wires that go from the rectifier-regulator to the solenoid, and often the insulation cracks with vibration and oil, which leads to a leakage of current to the mass, and if there are no visual defects, we move to instrumental diagnostics.

Diagnosis by multimeter: measurements of resistance and voltage

For a precise diagnosis, you'll need a digital multimeter. First, we measure the resistance of the windings. Unplug the connectors from the solenoid and put the device into resistance measurement mode (Ohms). Normal values vary by manufacturer, but are usually 1.5 to 3 Ohms for the traction winding and slightly higher for the retention one.

If the multimeter shows infinity (break) or zero (short circuit), the coil must be changed. It is also important to check for voltage when scrolling the starter. Connect the probes to the contacts of the connector (not the solenoid itself, but the wiring of the motor) and ask the assistant to spin the starter.

Table of typical values for diagnosis:

Parameter	Normal value.	Deviation	Action.
Resistance of the coil	1.5 - 3.0 Ohm	∞ or 0 ohms	Solenoid replacement
Start voltage	10 - 12 volts.	< 8 volts	Checking of the battery and wiring
Stock's move	3 - 5 mm	Jammed.	Cleaning or replacement
Current consumption	up to 4 Amps	> 6 Ampere	Short circuit.

Stress measurement nuances

When measuring the voltage, it is important to understand that it is only applied when the starter is scrolled, and if you just turn on the ignition, there may be no voltage on the suction wire, since the circuit is closed through the starter relay controller.

Substitution and adjustment of the node

If the diagnosis shows a malfunction, the solenoid needs to be replaced. The procedure is quite simple and requires no special skills, except for accuracy. It is important not to lose springs and washers that can fly apart when dismantled. Before installing a new unit, it is recommended to blow the carburetor seat with compressed air.

When installing a new solenoid, it is critical to correctly set the length of the rod: a too long rod will not allow the damper to close completely, causing a fuel overflow; too short will not open the suction enough to start; adjustment is done by twisting or twisting the plastic tip on the rod.

Algorithm of actions during replacement:

• 🔧 Unplug the battery and remove the fuel ramp or carburetor (if access is restricted).
• 🔧 Unscrew the two solenoid fastening bolts and disconnect the electrical connector.
• 🔧 Install a new solenoid, pre-lubricating the rod with a light silicone lubricant.
• 🔧 Connect the wires and conduct a test run, monitoring the work of the valve.

Specifics for different motor brands

While the way we work is the same for everyone, the designs of brands are different. Tohatsu and Nissan Solenoids are often integrated into a single unit with a regulator, which makes it easier to install, but makes the unit more expensive to replace. circuitry It may differ in the number of wires.

Motors. Yamaha They often use a separate solenoid attached directly to the carburetor body, and the design feature is that they have an extra spring of return, which eventually loses its elasticity. Suzuki It is worth paying attention to the tightness of the connector, since it is located in the zone of active water splashing during the boat.

Some Chinese manufacturers (in particular)Parsun, Hidea) use universal solenoids, which are suitable from Japanese counterparts, but require careful fitting along the length of the rod. Always compare the labeling of a new part with the old one before buying.

Frequently Asked Questions (FAQ)

Can I drive with a faulty solenoid suction?

Theoretically, you can if the engine warms up, but this is not recommended. If the solenoid is faulty, it will be difficult to start the engine in a cold state, and working on a rich mixture will lead to rapid contamination of candles and increased fuel consumption.

Why does the solenoid sucker burn?

The main reasons: moisture entering the body, voltage surges in the onboard network (fault of the voltage regulator) or mechanical jamming of the rod, because of which the coil works in a short circuit mode.

How to check a solenoid without a multimeter?

You can apply 12V voltage directly from the battery to the solenoid contacts (observing polarity if there is one, although often they are nonpolar). A valid solenoid should emit a loud click and draw in the stem.

Does the octane number of gasoline affect the work of the solenoid?

There's no direct effect, because it's an electromechanical node, but using poor-quality fuel with impurities can lead to the formation of a suction needle, which will make it difficult to move and put a strain on the solenoid mechanism.