How to set the ignition on a 4t scooter? Problems with the ignition of a 4-stroke engine can appear for various reasons, but all of them lead to the same result - the engine stops starting. But the lack of a timely spark may not be the only reason that the engine will not start. To accurately verify that it is ignition that causes the engine to fail, you must check all other possible malfunctions that may impede the operation of the engine and eliminate them. Failures may appear in the ignition system, the causes of which can occur both from the side of mechanics and from the side of the electrician. Using simple tricks, you can determine whether the problem is a mechanical malfunction, or whether the electrical component is to blame. At home, you can eliminate any breakdown in the ignition system of a 4-stroke scooter engine.
Reasons for a 4-stroke scooter engine failure
If the scooter engine does not start, then the reasons can be very different:
1. There is no fuel supply to the combustion chamber.
2. The air supply is not adjusted.
3. There is no compression. Burnt and deformed valves do not provide compression. The reason for the lack of compression may be improper assembly of the cylinder-piston group, as well as a malfunction of the cylinder itself.
4. Faulty gas distribution mechanism responsible for the operation of the valves.
5. Defective spark plug.
6. The ignition spark is not generated during the mechanical operation of the generator.
The principle of operation of the ignition on the engine of a 4-stroke scooter
Ignition on a 4t scooter depends on the synchronous movement of the camshaft located in the cylinder head and magneto. On the outside of the rotor housing there is a protrusion in contact with the ignition sensor during rotation. At the moment of contact, a spark arises on the candle. The rotor is connected to the crankshaft. When a spark occurs, the crankshaft and piston are in the extreme dead center position. How to set the ignition on a 4t scooter? It is necessary that during the passage of the dead point the position of the camshaft corresponds to the moment of ignition of the fuel in the combustion chamber.
Getting started to adjust the ignition
Before setting the ignition on a 4t scooter, you need to make sure that there is a spark and the candle is working. To do this, unscrew the latter, connect it to the ignition cable and press the metal body to the frame. When the rotor rotates, a clearly visible spark should appear, the presence of which indicates the proper functioning of the generator, as well as the candle itself.
4t Scooter Ignition Adjustment
In order for the rotation of the generator rotor and the camshaft to correspond to the desired piston operation cycle, it is necessary to set their position according to the marks. On the magneto body there is a marker of the dead center of the cylinder in the form of the letter "T". The rotor can be set manually, it can also be done using the kick starter. The position of the camshaft is determined by the marks on the timing star. Three points, drawn on the star from the outside, form an equilateral triangle, the top of which should be directed to the extreme position from the piston. Ignition adjustment consists in setting the correct position of the timing star.
Ignition timing
How to set the ignition on a 4t scooter ahead of schedule? There is an opinion that if you do this, then the speed and power of the motor will increase. In theory, it is. If a spark at the time of compression will occur a little earlier than the moment the cylinder passes the dead center, this should give the desired effect. But the technical implementation of such an ignition setting on a scooter is associated with the transfer of its protrusion on the generator rotor housing. There is a method that is simpler and safer, which gives a certain effect. You can make a step on the ledge of ignition. To do this, remove a layer of 0.5 mm from half the surface of the protrusion. The step should begin from the side that first contacts the ignition sensor. The double spark resulting from this will provide a more predictable engine start, as well as increase the likelihood of ignition due to adverse weather factors and improper fuel and air supply settings.