Honda dio 34 reed valve removal

Valve operation on various models

Often the model of scooter will determine how durable the reed valve installed will be.
Honda stands out in that there are practically no problems with this mechanism. This is facilitated by the materials used in manufacturing - rubber for the body, fiberglass for the plates. On scooters produced by Peugeot and Yamaha, on the contrary, the part very often becomes unusable, again due to the materials. The plastic body and metal petals do not interact well with each other; over time, the saddles are knocked out by the plates, and the unit stops performing its direct function. Therefore, on such vehicles it is better to tune the valves immediately, since the factory layout will not be enough. Timely replacement of the plates, even if done immediately after purchasing the scooter, will not allow a broken valve to damage the entire motor. The best alternative to metal petals would be carbon ones.

Reed valve on a scooter

Most scooters are equipped with two-stroke engines, so a check valve is installed on them. The reed valve is designed specifically for such motors. A similar mechanical unit is not installed on a four-stroke unit, since valves are responsible for the distribution of both fuel and exhaust gases. And in the push-pull model, this process is controlled by a resonator. Therefore, for most scooters produced, the valve is an important integral part.

If the motor on a moped is malfunctioning, there is no longer enough traction, or it won’t start at all, one of the primary tasks is to check the degree of suitability for use of a part such as a reed valve.

On a scooter, it is very important to monitor the performance of the part, because the slightest breakdown can lead to further serious problems. If it is broken or erased, the seal is lost, and accordingly, fuel enters the carburetor and engine, and from there into the air filter

This may result in loss of response to throttle adjustments. If a valve malfunction is determined, both repair and replacement of the unit are possible. You can purchase petals separately and replace worn ones with new ones. Or change the valve entirely, which is quite simple to do. It is necessary to dismantle the carburetor by finding the installed part in the pipe. Then remove the valve. It's a pretty simple process.

Design and connection of a Yamaha scooter carburetor

The Yamaha Jog scooter is one of the most popular on the Russian market: this is explained by the simplicity and reliability of the model, and its affordable price. The carburetor design of this scooter is standard, so you can figure it out using the description given above. However, when installing it, inexperienced owners may encounter some difficulties, which we will help you sort out.

The device is worth considering in more detail. This will help you understand not only how to adjust the carburetor and use it correctly, but also how to connect it correctly.

A starter enricher is attached to the carburetor body: it is small in size and housed in a plastic case. It has two bolts with rubber seals. The enricher is powered via a 12 V battery. This device is used to start the engine when cold, as it allows you to automatically enrich the mixture with oxygen.
The fitting is connected to the fuel supply hose coming from the gas tank tap.
If the enrichment unit needs to be removed, you will need to not only unscrew the bolts, but also disconnect the electric valve, to which there are only two wires.
The mixing chamber has a special cover to which a bolt is attached. If you unscrew it, you can get to the throttle valve. This allows you to check whether the throttle cable is connected, and also to get to the needle that regulates the level of fuel and air supply. If the carburetor needs cleaning, you will definitely need to remove the throttle.
The enrichment connector has two wire outputs, the yellow one is connected to the generator, the green one goes to ground. In principle, if you reverse the polarity, nothing will happen and the device will still work.
For the enricher to operate, voltage must come from the battery. When the element inside the device heats up, the needle will extend.
A special fitting is connected to the air filter, and there is a rubber elbow between them.
There are several screws on the carburetor body with which you can adjust the idle speed and mixture quality.
The float chamber is screwed from below and has 4 mounting bolts.
There is an additional fitting for oil supply: it is the smallest.
The second fitting is needed for communication with the atmosphere; you do not need to put anything on it.
The third one is connected to a gas hose. It goes to the gas tank vacuum valve.

How to check the solenoid valve on a scooter

Let's try to figure out how to check the solenoid valve on a scooter or moped.

This is a simple operation. Let's start in order:

You should check whether the enrichment channel is closed by the solenoid valve needle. Start the cold engine and observe the change in idle speed. At first they are increased and then decreased to the desired frequency. In this case, you can make a conclusion about the serviceability of the starting enrichment and not search for its faults;
If the scooter starts without problems, but the engine speed does not decrease after reaching operating temperature and remains high, there is a high probability that the starting enrichment is faulty. In this case, it is necessary to check the functionality of the solenoid valve;

Checking the solenoid valve on a scooter

If the power unit can be started only after long and exhausting presses on the kickstarter, the carburetor is not clogged, the gasoline level in the float chamber is set correctly, and the compression has not dropped, then most likely there are problems with the operation of the starting enrichment, and it needs to be checked.

So, we have come close to testing the scooter's starting enrichment for operability. To perform this operation, it is necessary to disconnect the wires connecting the solenoid valve to the scooter's electrical network. Then you should unscrew the fastening of the solenoid valve to the carburetor body and remove it. Next, you will need to prepare a pair of insulated wires, the length of which will allow you to connect the terminals of the starting enrichment to the battery.

When connecting, there is no need to observe polarity, since the solenoid valve is powered from an alternating voltage network

It is important to pay attention that the ends of the wires freed from insulation do not touch each other. All that remains is to connect the wires to the chips and supply 12 volts from the battery to the enrichment

With a working enrichment device, after a couple of minutes you can see the needle gradually moving out of the device body. The amount of stroke can be determined by measuring the extension of the rod before applying voltage and after turning off the power. For a faulty solenoid valve, five minutes after connecting to the battery, the needle will remain in the same position. If there are no defects in the wiring, then we can conclude that the enrichment unit is faulty.

Don’t be upset and try to repair the solenoid valve - the cost of a new one, depending on the model of the moped, varies between 5-7 dollars. When purchasing, it is advisable to have an old starting enrichment with you or clearly find out from the seller whether the spare parts he offers correspond to the brand of the scooter.

How does a scooter carburetor solenoid valve work?

The starting enrichment on a 2t scooter and on a four-stroke moped works according to a fairly simple algorithm. On a cold power unit, the spool needle occupies the upper position. It is responsible for opening the fuel channel, and the position of the damper affects the volume of supplied air. The first revolutions when starting the engine cause a vacuum inside the emulsion channel, and gasoline is sucked into the engine.

The result is a highly enriched mixture, making it easier to start a cold engine. Before reaching operating temperature, the power unit needs to be fed with an enriched mixture.

The enricher in this mode performs the function of a parallel carburetor - fuel entering through the nozzle is mixed with air and directed to the engine.

The current generated by the generator of the running engine is supplied to the contacts of the heater that controls the thermoelectric valve of the intake system. Due to heating, the temperature of the powder drive increases, which causes the rod to gradually extend up to 4 mm. The force is transmitted to the pusher, which ensures the movement of the damper.

The starter enricher on a scooter works according to a fairly simple algorithm.

As the engine warms up, the spool with the needle lowers, followed by the air-fuel channel closing. After five minutes, the damper closes completely and the mixture becomes lean. Now the gasoline enrichment system on a warm engine is regulated by the carburetor.

After stopping the engine, the valve stops heating, and as a result of powder compression, the damper drive using a pusher and rod returns it to its original position. The system is ready for subsequent startup. The cooling and return process takes no more than two minutes. The enricher has a drawback - it works separately from the motor.

As a result, in the warm season, on a hot engine that does not need a rich mixture, the engine, when the thermoelement has cooled, is powered by a rich mixture.

Signs that a check is needed

If difficulties arise with starting the engine and in a number of other situations, it is necessary to be able to check the functionality of the starting enrichment. Thoughts about a malfunction of the solenoid valve may arise in different cases.

Let's take a closer look at the main reasons:

the first morning start of a cold scooter engine is problematic;
it is difficult to start a cooled scooter engine after a long stay;
fuel consumption significantly exceeds the consumption indicated in the passport;
The scooter's power unit is quite unstable at idle;
a warm engine does not maintain speed, and a cold engine functions intermittently.

A faulty enrichment device can be in two positions:

with the solenoid valve needle constantly extended;
in the initial state, when the needle does not protrude.

It is necessary to be able to check the functionality of the starting enrichment if difficulties arise with starting the engine.
Each case has a different effect on the operation of the motor. The first situation makes it difficult to start the engine of a cold scooter. An attempt to start the engine by pressing the kickstarter, as well as starting with an electric starter, are unsuccessful. In the second case, the engine starts without problems, but during operation it consumes an increased amount of gasoline. Increased fuel consumption is associated with engine operation on a highly enriched mixture.

Starting enrichment on a 4t scooter - description and purpose

Not all motorcycle enthusiasts know what an electric valve on a scooter is for. This device is also called a starting enricher. It is responsible for the volume of the air-fuel mixture, which fills the cylinder chamber through a nozzle when starting a cooled scooter engine. A feature of small-capacity motorcycles is the engine’s need for a rich mixture during a cold start of the scooter engine. The fuel entering through the carburetor is mixed with air in a certain concentration thanks to an electric valve connected to the carburetor.

The starting enricher is responsible for the volume of the air-fuel mixture

If the starting enrichment is functioning and there are no breakdowns of the power unit, starting the engine is not a problem even in the cold season. There is no doubt about the importance of the electric valve in ensuring trouble-free starting of the engines of modern mopeds and scooters. However, if difficulties arise with starting the engine, interruptions in operation and excessive power consumption of the engine, it can be assumed that problems have arisen with the starting enrichment. That is why it is important to know its structure and be able to check its functionality.

Reed valve on a scooter - purpose, design features, breakdowns

The reed valve is located between the carburetor and the scooter engine in the intake manifold. The design of the location may vary significantly depending on the vehicle model, but the essence remains the same.

If you are the owner of a two-stroke scooter, you are used to carrying out its maintenance yourself, for example, cleaning the carburetor; in case of the above problems, do not be lazy to check the reed valve. It's very easy to get to. After dismantling the carburetor, take the time to also remove the inlet pipe. Below it you will see this most treasured petal valve.

Each scooter manufacturer has its own ideas about its shape and design; its shape can be single-slope or double-slope, in the form of a house, but the operating principle is the same in any case and the testing process is no different.

Check the condition of the petals; they should be perfectly smooth, without waves or distortions. There should be no cracks or chips. The petals should fit tightly to the saddle, the presence of gaps is excluded here. There shouldn't be any dirt either. For example, even a small grain of sand that gets under the petal valve can lead to serious interruptions in the operation of the scooter engine

Why adjust the carburetor?

Carburetor adjustment may be required in the following cases:

The spark plugs are serviceable, but do not work very well; their color has changed to black or yellowish.
The engine does not provide the required power
Scooter won't start
Fuel consumption has increased excessively.

All these problems in most cases are caused by an insufficiently enriched or, conversely, overly enriched mixture with oxygen, and they can be corrected by correctly adjusting the carburetor.

The settings, regardless of whether you have a 2t or 4t scooter, have three phases and are made as follows:

Idle speed adjustment
Setting the fuel level
Adjusting the quality of the mixture.

On some carburetor models there is no screw that adjusts the fuel quality, so you have to disassemble the carburetor to change the position of the needle.

The idle speed adjustment is carried out after the engine has warmed up: this takes no more than 15 minutes. For this purpose, the design provides an idle screw. It allows you to make the engine stable by selecting the desired idle speed. When the screw is tightened, the speed will increase, and when it is rotated counterclockwise, it will decrease.

It is important to adjust the quality of the mixture. If it is too lean, the scooter will ride with difficulty, and the engine will noticeably lack power. If the mixture is too rich, the spark plugs will turn black and quickly fail. Fuel quality adjustment is usually carried out using a screw located on the carburetor body. To enrich it you need to turn it clockwise, to lean it counterclockwise. If there is no screw, the carburetor is opened, the locking ring on the needle moves up for a richer mixture, down for a leaner one.

Adjustments are made as follows:

Start the engine and warm it up for 10 minutes, after which you need to turn it off
The screw must be tightened clockwise until it stops, but without force.
After this, it is unscrewed counterclockwise 1.5 turns
The engine needs to be started and the screw turned an additional 1/3 turn in the same direction. Wait 2 minutes
As the speed increases, you need to unscrew the screw an additional 1/4 turn and observe the reaction for about 2 minutes. If the speed does not drop, repeat the steps
If the speed begins to decrease, the screw must be turned clockwise 1/4 turn.

Ideally, the engine will operate exactly at 1.5-2 propeller revolutions, but its position depends on the quality of the fuel. In the case of a needle, the quality of the mixture will vary depending on the position of the needle locking ring. The disadvantage of such a carburetor is the small number of needle positions and the need to disassemble it each time to make adjustments.

You can adjust the fuel level in the chamber as follows:

Unscrew the drain screw
The phone is lifted up
You need to check the fuel level while the engine is running. The melting level is slightly below the skirt located on the float chamber cover
Most often, the level rises above normal and the carburetor overflows, so you need to adjust the float so that it fires earlier. To do this, the needle holder is usually bent. A lot of force is not required, only a few mm are needed.

Honda Dio AF-25 SR (Part 11) — Some breakdowns (reed valve and wiring) — DRIVE2

Recently the scooter has become bad and hard to start, about 15 times, and then only with gas. The idle is no longer adjustable with the screw on the carburetor. Where I haven’t climbed yet... it’s in the reed valve, it supplies the mixture to the cylinder at the right moment.

If the petals are not working properly, then the mixture will not be sucked in correctly, and hence the interruptions. I removed the valve (to remove it, you need to disassemble the floor of the moped + remove the carburetor)

And this is what I discovered, a valve of 3 petals, two of them do not fit tightly, and there is a gap, that is, they allow air to pass to the carburetor.

There is a good video here. Grandfather tells how he repaired his petal valve by setting it up again. In the video everything is easy and simple... I decided to try it.

In short, I polished and polished the plate so that it would press the petals differently, and this way and that... nothing worked. In the end, I decided to adjust each petal separately, for this I needed metallic adhesive tape that is not afraid of temperature, and it is thin, you can adjust it in layers in certain places pressing each petal.

In short, I spent a lot of time, and all I managed to do was far from ideal, but it was better than it was.

But this did not solve the problem. Okay, we'll figure it out further...

Somehow, while riding, I noticed that my tank needle was at 0... although when leaving I remember there was half a tank... I think okay, I’ll go to a gas station right now and fill it up full. I filled it up...the arrow just lay there...and then I realized that there was something wrong with the wiring or the sensor.

And later I noticed that the turn signals, signal, starter, stop, fuel level did not work. And only the front headlight, instrument lighting, and taillight worked.

But then I found the asshole, one ground wire came off the terminal, black. I clamped it again, in the state it was not clamped very tightly and just fell out of the terminal.

And everything started working right away. beauty

Tools

Small pliers or special wrench
Open-end wrench 9
14mm socket wrench or socket
Socket wrench 8
A set of measuring probes, preferably with a pitch of 0.02 mm

We free access to the cylinder head: depending on the scooter model, we remove the hood or seat tank. We find the valve cover there, unscrew the four 8mm bolts and remove it from the engine.

The valve cover looks like this. In my case, to get to it I had to remove the hood, saddle and seat tank.

There is a generator casing on the right side of the engine - remove it. If you are too lazy to remove it, just take out the plug. The plug is located in the upper part of the case and can be removed using a regular screwdriver. Through the plug we will control the position of the marks on the rotor.

We insert a 14 mm socket wrench into the center of the generator casing and turn the engine (clockwise) until the “T” mark (from the English “Top” means top, in our case the piston position is at TDC) on the generator rotor is exactly opposite the ledge.

After the mark on the generator coincides with the ledge on the engine crankcase, we check what position the camshaft is in. The camshaft should be in a position where both valves are closed. And it gets into this position every second revolution of the crankshaft since it rotates twice as slow.

The correct position of the camshaft is determined by its sprocket. The sprocket should become the large hole facing up, and the small holes and the marks that are knocked out near them should become parallel to the plane of the valve cover connector.

This is ideal, but in practice the asterisk rarely becomes the way we need it. And the chain is often to blame for this - it stretches and the camshaft begins to slightly not catch up with the crankshaft. If your sprocket has become a little crooked, then by and large it’s nonsense. But if you have it for some reason, then this problem needs to be solved very quickly - otherwise sooner or later the valve will bend.

Electrics and electrical equipment of a scooter

Dedicated to all owners of Chinese scooters...

To begin with, I would like to present a wiring diagram for a Chinese scooter.

Since all Chinese scooters are very similar, like Siamese twins, their electrical circuits are practically no different.

The diagram was found on the Internet and is, in my opinion, one of the most successful, since it shows the color of the connecting conductors. This greatly simplifies the diagram and makes it more comfortable to read.

(Click on the image to enlarge. The image will open in a new window).

It is worth noting that in the electrical circuit of a scooter, just like in any electronic circuit, there is a common wire . On a scooter, the common wire is the minus ( - ). In the diagram, the common wire is shown in green . If you look more closely, you will notice that it is connected to all the electrical equipment of the scooter: headlight ( 16 ), turn relay ( 24 ), instrument panel backlight lamp ( 15 ), indicator lamps ( 20 , 36 , 22 , 17 ), tachometer ( 18 ), fuel level sensor ( 14 ), horn ( 31 ), tail light/brake light ( 13 ), start relay ( 10 ) and other devices.

First, let's go over the main elements of the Chinese scooter circuit.

Egnition lock.

Ignition switch ( 12 ) or “Main switch”. The ignition switch is nothing more than a regular multi-position switch. Even though the ignition switch has 3 positions, the electrical circuit uses only 2.

When the key is in the first position, the red and black wires are connected. In this case, the voltage from the battery enters the electric circuit of the scooter, the scooter is ready to start. The fuel level indicator, tachometer, sound signal, turn relay, and ignition circuit are also ready for operation. They are supplied with power from the battery.

If the ignition switch malfunctions, it can be safely replaced with some kind of switch like a toggle switch. The toggle switch must be powerful enough, because the entire electrical circuit of the scooter is, in fact, switched through the ignition switch. Of course, you can do without a toggle switch if you limit yourself to short-circuiting the red and black wires, as the heroes of Hollywood action films once did

1 is shorted to the housing (common wire). In this case, engine operation is blocked . Some scooter models have an engine stop button ( 27 ) to block the engine, which, like the ignition switch, connects the white- black and green (common, body) wires.

Generator.

The generator ( 4 ) produces alternating electric current to power all current consumers and charge the battery ( 6 ).

There are 5 wires coming from the generator. One of them is connected to a common wire (frame). The alternating voltage is removed from the white wire and supplied to the relay regulator for subsequent straightening and stabilization. The yellow wire removes voltage, which is used to power the low/high beam lamp, which is installed in the front fairing of the scooter.

Also in the design of the generator there is a so-called hall sensor . It is not electrically connected to the generator and there are 2 wires coming from it: white- green and red - black . The hall sensor is connected to the CDI ignition module ( 1 ).

Relay regulator.

Regulator relay ( 5 ). People may call it a “stabilizer”, “transistor”, “regulator”, “voltage regulator” or simply “relay”. All these definitions refer to one piece of hardware. This is what the relay regulator looks like.

The relay regulator on Chinese scooters is installed in the front part under a plastic fairing. The relay-regulator itself is attached to the metal base of the scooter in order to reduce the heating of the relay radiator during operation. This is what the relay regulator looks like on a scooter.

In the operation of a scooter, the relay regulator plays a very important role. The task of the relay regulator is to convert the alternating voltage from the generator into direct voltage and limit it to 13.5 - 14.8 volts. This is the voltage required to charge the battery.

The diagram and photo show that there are 4 wires coming from the relay-regulator. Green is the common wire. We have already talked about it. Red is the output of positive DC voltage 13.5 -14.8 volts.

The regulator receives alternating voltage from the generator through the white wire to the relay. Also connected to the regulator is yellow wire coming from the generator. It supplies the regulator with alternating voltage from the generator. Due to the electronic circuit of the regulator, the voltage on this wire is converted into a pulsating one, and is supplied to powerful current consumers - the low and high beam lamps, as well as the dashboard backlight lamps (there may be several of them).

The supply voltage of the lamps is not stabilized, but is limited by the relay regulator at a certain level (about 12V), since at high speeds the alternating voltage supplied from the generator exceeds the permissible limit. I think those who have had their dimensions burned out due to malfunctions of the relay-regulator know this.

Despite all its importance, the device of the relay regulator is quite primitive. If you pick apart the compound with which the printed circuit board is filled, you will find that the main relay is an electronic circuit consisting of a thyristor BT151-650R , a diode bridge on 1N4007 , a powerful diode 1N5408 , as well as several wiring elements: electrolytic capacitors, low-power SMD transistors, resistors and a zener diode.

Due to its primitive circuitry, the relay-regulator often fails. Read about how to check the voltage regulator here.

Photo report: Adjusting valves on a Chinese scooter (139QMB, 157QMJ)

During operation of a four-stroke air-cooled engine (such engines are found on most Chinese scooters and motorcycles), the cylinder head (hereinafter referred to as the cylinder head) can heat up to 260 degrees. This is, of course, not the operating temperature, but this is often the peak temperature.

The valves that are located directly in the cylinder head itself heat up in the same way as the head, with the only difference that the intake valve heats up a little less since it is cooled by the working mixture, and it is ordinary atmospheric air saturated with gasoline vapors, and the exhaust valve heats up much more. Since a flow of exhaust gases passes through the exhaust valve, the temperature can reach 600 degrees.

The problem is that metal parts expand when heated. Valves are no exception: during operation, the valve heats up and becomes a little longer. And when the valve becomes longer, it simply rests against the gas distribution mechanism and opens a little, or rather does not close completely (squeezed), due to which gases under high pressure seeping through leaks melt the working edges of the valve and its seats.

The edges of burnt valves look something like this.

By the way, not only the valves burn out, but also the sockets in which they sit

And this is what the working edges of valves and seats look like after repair.

As you can see, there is little point in regulating something that has already gone bankrupt for a long time. A burnt-out valve will no longer hold compression. And if you find that one of the valves has been jammed, then feel free to remove the head and grind the valves, otherwise there will be no point.

Operating principle of a membrane enricher

The membrane starting enrichment works on a different principle. When the engine is not warmed up, the valve is in the open position. Starting the engine causes a vacuum in the area of the intake manifold, which is transferred to the membrane thanks to the thermal valve. Under the influence of reduced pressure, the membrane tries to rise, opening a channel responsible for supplying additional air volume.

Further heating of the cylinder to operating temperature causes the valve to close and lower the spring-loaded valve associated with the needle. As a result, the supply of additional fuel is cut off. Such a system with a membrane functions in a clear connection with the engine temperature, which ensures a more correct dosage of fuel.

The membrane starting enrichment works on a different principle.

Why adjust valves?

Many “riders”, when purchasing equipment, have little interest in its needs, which leads to rapid engine breakdown. The role of the valves is to supply the air-fuel mixture to the combustion chamber and remove exhaust gases. They operate under constant temperature conditions, and as you know, when heated, the metal begins to expand. Thermal expansion, together with gap deviation, leads to the fact that the valve may not close completely and the pusher is pinched, or vice versa, to too large a gap between the pusher and the valve.

If the intake valve has too large a gap between the pusher, then the combustion chamber is filled less with the mixture and the pusher breaks, and if the exhaust valve, the ventilation of the cylinder deteriorates. In both cases, this is felt as a loss of power and dynamic characteristics of the engine. When we talk about excessive clearance, then in this case the consumption may increase and a characteristic clattering sound can be heard.

That is, the engine requires adjustment of the gaps if:

hard to start;
does not start;
stalls while driving;
starts and stalls;
consumption has increased;
the maximum speed has decreased;
a clattering sound is heard at the gas distribution mechanism;
500 km have passed since replacing the piston and cylinder group.

Installation of equipment on the heating system

Often, devices of this type are used when piping boilers located in the heating system. The relevance of this issue increases at the moment when it becomes necessary to connect several heat generators in a cascade or make the operation of several boilers simultaneously synchronized.

The installed valve will not allow the formation of parasitic flows inside the system, which often arise when parallel heat sources are turned on. Provided that the supply of the working medium will be carried out through a mounted pump, any of the known schemes for its installation using shutter mechanisms can be used.

When using gravity systems, it is recommended to give preference to reed or gravity valves. The rules for installation when using such equipment are the same. However, before purchasing all the necessary auxiliary components, you need to find out as much information as possible about the characteristics, compare with several similar units and get full advice from a specialist on this issue.

Communities › Daewoo Matiz Club › Blog › Intake and exhaust valves are jammed! Because of which ?

Hello everyone, please give me some advice! The first time I got into the engine to adjust the valves was at 70,000 miles, they did everything well, but I didn’t notice much of a difference! At a mileage of 83 thousand, problems arose with cold starting, everything is described in detail in my blog, so after starting the engine doubled and ran very unstable, I rushed to change it from the simplest: spark plugs, high voltage wires, both gasoline filters, washed the injectors, distributor cap, nothing did not help ! I went to the service station where they immediately told me that the valves needed to be adjusted, they did it, it turned out that the valves were clamped, the gaps were set to 0.20 and 0.30, but after 3250 km the engine started working unstably again when cold, under warranty they did the adjustment again, again all the valves were clamped! The question is why, is it really the problem with the seats or the valves themselves? As a result, they told me to come and check the gaps after 2000 km! Thank you in advance !

Where is the Reed Valve on a Scooter?

Troubleshooting the scooter's power system

When troubleshooting a scooter’s power system, it is assumed that the central piston group of the scooter is in order and creates sufficient vacuum at the inlet to “draw” gasoline into the combustion chamber, as well as the integrity of the scooter’s crankshaft seals and the spark plug are also in order.

To find out whether gasoline is entering the combustion chamber, the most common method is to unscrew the spark plug and make sure that it is wet. If the spark plug remains dry even after several confident pumpings with the kick starter, you need to go from the very beginning of the power system: find out whether gasoline is flowing from the tank to the scooter’s carburetor.

To do this, remove the gas hose from the carburetor and direct it into some container.

My account

You should monitor the tread height of your tires and replace them as necessary. Riding a scooter with worn tire tread is extremely unsafe.

The turn should be done “pull”, controlling the gas or releasing it in advance. Always turn on low beam headlights when riding a scooter.

Float chamber It is important that the fuel in the float chamber is always within certain limits and does not drop below the permissible norm. It is also important that gasoline does not rise above the permissible standards - this will help to avoid overfilling.

Actually, the float, which on the opposite side has a shut-off needle at its disposal, is responsible for the optimal level of fuel in the float chamber. Gasoline filling the chamber raises the float as it enters, which is constantly afloat.

cleaning the carburetor Honda Dio 27

When it reaches its maximum fulcrum, it closes the channel through which gasoline is directed from the gas tank to the carburetor. This is how the stable presence of a small amount of gasoline in the float chamber is regulated.

These are probably all the main systems of the Honda Dio 27 carburetor, so once you understand the operation of this device, it will not be difficult for you to put your scooter in order using the instructions in the manual.

Why is such fittings needed?

During the operation of heating systems, there is a risk of hydrodynamic pressure surges in certain sections of the pipeline. As a result, a reverse flow may form when the direction of the main flow changes. When installing such a unit on a bypass, such emergency situations can be avoided, achieving the necessary uninterruption of the operating system. The equipment is designed to prevent the formation of reverse movement of the thermal fluid

There are several varieties of such fittings, so it is extremely important to make the right choice

The valve used must facilitate the unimpeded passage of the coolant, preventing the formation of reverse movement, and without affecting the technical and operational characteristics of the system used.

How does an electric valve work on a scooter?

To enrich the fuel-air mixture, a fuel enrichment device with a mechanical drive and an automatic control system is used. Let us consider the operating principle and features of each of these enrichment systems.

Manual

The manual enrichment system, which requires precise adjustment, is inconvenient to use. To start the scooter engine after parking overnight, you need to press the lever on the steering wheel, which transmits force through the cable to the pusher. After the power unit starts, warms up and reaches operating temperature, it is necessary to return the manual enrichment lever so that the volume control flap and needle return to their original position. As experience in operating scooters shows, such a system has a number of inconveniences.

Most models of modern mopeds are equipped with an automatic starting enrichment

Auto

An automatic type start-up enricher, called a thermoelectric valve, is installed in most models of modern mopeds with two-stroke and four-stroke engines.

The device consists of the following parts:

housing in which the solenoid valve is located;
ceramic heater powered from the on-board network;
spring-loaded drive with a rod connected to a pusher and a valve.

The device is connected to an air channel that saturates gasoline from an additional float chamber before feeding it into the combustion chamber of the cylinder. One feature of scooter carburetors should be noted. They have two float chambers - additional and main, connected to each other by a starting jet.

A small tubular channel from the additional float chamber is connected to the mixing chamber, which is responsible for supplying air with gasoline to the engine. The cross-section of the mixing chamber is blocked by a valve, structurally similar to the throttle valve in a carburetor. Lowering the damper causes the spring-loaded needle to move, closing the fuel supply channel. The solenoid valve body is thermally insulated and located in a rubber boot. All modern scooters have a similar thermoelectric valve design.

Old scooter models are equipped with a starting enrichment without electric heating

Older scooter models are equipped with a starting enricher without electrical heating. The transfer of thermal energy to the drive is carried out thanks to a copper heat-conducting cylinder connected to the scooter motor. Instead of a powder drive, a membrane drive is installed. In this case, the intake manifold of the cylinder head is connected to one cavity of the bulb.

The principle of operation of the scooter carburetor solenoid valve

When the engine is cold, the valve with the spool needle 6 is raised as high as possible (open). The needle opens the fuel supply channel, and the flap opens the air supply hole. At the first engine revolutions, a vacuum is created in the emulsion channel and gasoline located in chamber 7 is sucked into the engine through channel A, causing a strong enrichment of the mixture and facilitating the first flashes in the engine. After the engine has started, but has not yet warmed up, it still needs a rich mixture. The enricher works like a parallel carburetor - gasoline enters it through jet 9, mixes with air and enters the engine.

When the engine is running, alternating current from its generator is always supplied to the contacts of the ceramic heater 2 of the thermoelectric valve of the starting system. Heater 2 warms up drive 3. As the engine and drive warm up, the rod gradually extends by 3 ... 4 mm and drives the damper through pusher 5. Thus, the engine warms up along with the thermoelectric valve, the spool with the needle drops and closes the air and fuel channels, and the mixture gradually becomes leaner. After 3...5 minutes, the damper closes completely and the degree of enrichment of the mixture on a hot engine is regulated only by the carburetor idle system .

When the engine stops heating of the valve stops , the damper drive cools down (the powder is compressed) and under the action of spring 10, pusher 5, rod 4 and damper 6 return to their original position, opening the channels for subsequent start-up. Cooling down and returning to its original position also occurs within a few minutes.

The disadvantage of this type of enrichment is that it operates separately from the engine. For example, very often, especially in warm weather, while the engine is still hot and there is no need to enrich the mixture, the thermoelement is already cooling down. We start the engine and it gets a rich mixture.

Operating principle of the second type of starting enrichment (with a membrane)

When cold, the valve is open . After starting the engine, a vacuum occurs in the manifold and is supplied to the membrane through a thermal valve. As a result of low pressure, the membrane rises and opens a channel for additional air supply. As the cylinder head warms up, the valve closes and the valve with the needle is lowered under the action of a spring, cutting off the additional fuel supply.

With this design principle, the connection with the actual engine temperature is maintained, and fuel dosage is carried out more correctly.

Adjusting valves on a scooter

Scooters with simple 50 - 150 cc engines have flooded the market and are now found on every corner. Why is this happening? First of all, they captivate with their low cost, unpretentiousness and every year the better and better quality of the main components and their assembly. Regardless of the year of manufacture, the entire scooter, and especially its motor, is subject to regular maintenance; this is the main requirement for maintaining the performance of the motors. One of the important adjustments that should be done regularly is adjusting the valves on a four-stroke scooter.

Many owners of scooters and motorcycles are afraid of this procedure due to ignorance and fear of damaging the engine. We believe that adjusting the valves on a 4t 80cc, 50cc, 150cc scooter is a task that any motorcycle owner can handle with a small set of keys and desire. Below, you will find step-by-step instructions on how to adjust the valves on a scooter with a 139qmb and 157qmj motor.

Source