Motoblock is now a fairly widespread technique. This article talks about the ignition system, how to configure it and what problems may arise during the operation of the device.
Motoblock ignition system
The ignition system is one of the most important components of the motoblock mechanism, its purpose is to create a spark, which is necessary for fuel combustion. The simplicity of the design of this system enables users to successfully try to repair or adjust it themselves.
Typically, an ignition system consists of a coil connected to a power supply, a spark plug and a magneto. When voltage is applied between the spark plug and the magnetic shoe, a spark forms, which ignites the fuel in the combustion chamber of the motor.
Electronic systems are also equipped with circuit breakers, which operate to cut off the power supply in the event of any malfunction.
How to set and adjust?
If your walk-behind tractor starts poorly, you need to pull the starter cord for a long time or the motor reacts with a delay, most often you just need to set the ignition correctly. The procedure is described in the manual of the device. But what if you don’t have it at hand and you don’t remember where you put this useful brochure ?
Correction of ignition on a walk-behind tractor often comes down only to regulating the gap between the flywheel and the ignition module.
Follow these guidelines.
Close the candle with a square, press its body against the cylinder head by turning this element of the ignition system in the opposite direction from the hole in the cylinder end. Turn the crankshaft. You can do this by pulling the starter cord. As a result, a bluish spark should slip between the electrodes. If you did not wait for the spark to appear, check the gap between the stater and the flywheel magneto. This indicator should be 0.1 - 0.15 mm. If the gap does not correspond to the set value, it must be adjusted.
You can try to install the ignition by ear, especially if you have it quite thin. This method is also called non-contact. To do this, start the engine, slightly loosen the distributor. Turn the breaker slowly on two sides. At maximum power and number of revolutions, fix the structure that defines the moment of sparking, listen. When you turn the chopper, you should hear a clicking sound. Then tighten the mount of the distributor.
You can use a strobe to adjust the ignition.
Preheat the motor, connect the strobe to the power circuit of the motoblock device. Place the sound sensor on the high voltage wire from one of the engine cylinders. Dismantle the vacuum tube and plug it. The direction of the light emitted by the strobe must be towards the pulley. Start the engine idle, turn the timer. Having ensured that the direction of the pulley mark coincides with the mark on the device cover, fasten. Tighten the breaker nut.
Prevention and troubleshooting
To prevent malfunctions in the ignition system, try to follow some simple recommendations :
- do not work on a motor-block device if the weather is bad on the street - rains, dampness, frost, or sudden changes in humidity and temperature are expected;
- if you feel an unpleasant smell of burned plastic, do not turn on the unit;
- protect important parts of the mechanism from water penetration;
- replace spark plugs about once every 90 days, if you are actively using the device, this period can and should be shortened;
- the oil used for the engine must be of high quality and suitable for the given model of the brand, otherwise the candle will be constantly filled with fuel;
- carry out regular inspections of the ignition system, gears, in order to prevent the use of the unit with broken cables, other malfunctions;
- when heating the motor, try to reduce the load on the device, so you protect the mechanism from accelerated wear;
- when you are not using the walk-behind tractor in winter, put it in a dry and fairly warm room under the lock, in order to prevent overcooling of the device.
What problems can arise?
The main problem is the lack of spark . Most likely, the cause is a candle - either a deposit has formed on it, or it is faulty. Unscrew it and carefully inspect the electrodes. If there is a deposit formed by filling with gasoline, in addition to cleaning the spark plug, it is necessary to check the fuel supply system, there may be leaks. If there is no spark, you need to clean the candle from soot. A good way out is to heat it over a turned-on gas burner, scraping from its surface frozen stains of the fuel mixture.
After cleaning the candle, test its serviceability. To do this, put a cap on top of the part and bring it, holding in one hand, to the motor block motor housing by a distance of about 1 mm. With your free hand, try to start the engine.
If the spark plug is in good condition, a long-awaited spark will form in its lower extremity, which will fly to the engine body.
Otherwise, check the gap between the electrodes. Try to insert a razor blade there, and in case the electrodes tightly clamp it, the distance is optimal. If there is free blade hanging, an adjustment of the position of the electrodes is necessary. To do this, lightly tap the back of the center element with a screwdriver. When the electrodes are in optimal position, try starting the motor again. If the spark does not appear, test the magneto for serviceability.
To test the magneto, after you have tested the plug, put on the tip of the plug with the drive in good condition. Move the lower end of the plug to the body of the magnetic shoe and begin to turn the flywheel of the motor. If there is no spark, there is a malfunction and the part requires replacement.
Other problems with the ignition system are possible:
- weakness or lack of spark;
- the unpleasant smell of burnt plastic in the part of the mechanism where the ignition coil is located;
- cracking when starting the motor.
All these troubles require a coil inspection. The best way out is to completely dismantle and inspect it.
To do this, unscrew the mounting bolts, remove the upper part of the ignition casing. Then unplug the power cord, pry the coil element out and pull it out. Carefully inspect the appearance of the part - the presence of black spots indicates that the current did not flow to the candle, but melted the coil of the coil. This situation is especially relevant for motor-blocks with non-contact ignition.
The cause of this malfunction is in poor-quality contacts on the high-voltage cable. It is required to strip or completely replace the wires . Devices with an electronic ignition system have an automatic fuse that cuts off power in the event of a malfunction. If your machine is equipped with any other ignition system, you will have to disconnect the cable yourself. If the spark breaks when turned on - check the tip of the candle, most likely it is dirty.
See how to adjust the ignition on the walk-behind tractor.