DIY scooter repair

A list of the most common scooter problems that you can fix yourself without the help of specialists.
Crime: the brake light does not light up, the brake lever limit switch does not work.
Analytics: the lever of one of the brakes has not been pressed or there is a malfunction in the brake light circuit.
Procedure: replace the bulb, adjust the brake lever free play or replace the brake lever limit switch.

Crime: fuse blown.
Procedure: check and, if necessary, replace the fuse for the main circuit and the starter circuit.

Crime: the junction of the terminal with the wire is covered with a loose coating of oxides.
Analytics: the battery gives insufficient voltage, which can happen due to a malfunction in the circuit or if the battery terminals are oxidized.
Action: check the circuit, recharge the battery if necessary. Clean the terminals from oxides.
A temporary measure is to start the engine with a kick starter.

Crime: you turned on the ignition, pressed the brake lever and the starter button, and the starter relay still does not click.
Analytics: the electric starter circuit is faulty.
Actions: clean the contacts on the relay and starter, "ring" the relay, wiring, starter windings.

Crime: when you press the kick-starter lever, it scrolls, but the engine crankshaft does not rotate; the leg does not feel resistance to the stroke of the kick-starter lever.
Analytics: Kick starter or ratchet gear teeth are broken. Action: replace defective parts.
Crime: the electric starter turns the crankshaft, but the engine does not start.
Analytics: the carburetor is "dry" (unscrew the drain screw of the float chamber - see). Variants of reasons: the filter of the gas valve is clogged, the gas valve is faulty, the fuel line is clogged, the vacuum hose for the control of the gas valve has jumped off or is leaking.
Actions: clean the fuel tap filter, blow through the fuel line, make sure that the automatic gas tap is in good working order.

Crime: fuel is supplied to the carburetor, but does not enter the pop-up chamber.
Analytics: float fuel valve stuck.
Procedure: remove the float chamber cover and clean the valve seat. If it does not help, replace the valve.

Crime: you unscrew the candle, and it is "wet" - covered with a layer of unburned benzo mixture.
Analytics: excessively rich combustible mixture, which happens due to too high fuel level in the float chamber or due to clogged air filter.
Actions: disassemble the carburetor, check the fuel level, clean the air filter.
Side effects: The engine starts immediately if a little gasoline is poured into the air filter.
Analytics: the automatic starting enrichment does not work.
Actions: check the serviceability of the starting enrichment (there are several ways - they are described in detail in the repair manuals)

Crime: a spark does not occur on a spark plug unscrewed from its socket (in a position where the metal part of the spark plug reliably contacts the "mass" of the scooter).
Analytics: the spark plug is faulty: the insulator is broken or the electrodes are covered with a thick layer of carbon.
Procedure: Clean the spark plug with emery paper or replace. If the spark still does not appear, diagnose other elements of the ignition system.

Crime: the spark on the spark plug is formed, but weak or "running".
Analytics: the insulator is broken at the spark plug.
Action: replace the spark plug.

2. THE ENGINE STARTS WITH LABOR, RUNNING UNSTABLE
Crime: the engine does not "spin", there are pops in the carburetor.
Analytics: excessively lean fuel mixture, a possible cause - air is sucked in through a loose intake manifold or damaged crankshaft oil seals. Water in the float chamber.
Procedure: replace the gasket under the branch pipe and evenly tighten the bolts of its fastening. Replace the crankshaft oil seals. Get rid of the water in the float chamber (by unscrewing the drain screw of the float chamber), blow out the jets and channels of the carburetor, replace the gasoline in the tank.

Crime: a spark on an unscrewed spark plug (in a position where its metal part reliably contacts the "mass" of the scooter) is formed, but the surfaces of the insulator and electrodes are dry.
Analytics: the automatic starting enrichment does not work (if the engine is cold). Normal combustible mixture does not form. The idle air jet is clogged.
Actions: check the serviceability of the starting concentrator (see item 1). Purge the carburetor jet and channels.

Crime: there are water droplets on the insulator and electrodes of a twisted spark plug. Analytics: water penetrated into gasoline.
Action: get rid of water in the float chamber.

Crime: a spark on an unscrewed spark plug (in a position where its metal part reliably contacts the "mass" of the scooter) is formed, but the surfaces of the insulator and electrodes are covered with black oily soot (photo 5).
Analytics: the brand of the spark plug does not correspond to the thermal mode of the engine operation - its glow rate is higher than that set for the given engine (the spark plug is "cold"). The temperature in the working area of ​​the plug is insufficient for self-cleaning of the electrodes.
Action: replace the spark plug with a "hotter" one (with a lower glow number).

Crime: the engine starts normally, but soon there are interruptions in its work and it stalls.
Analytics: the vent hole in the fuel tank cap is clogged or the hoses responsible for communicating the contents of the gas tank to the atmosphere are clogged.
Procedure: Clean the fuel tank cap vent or hoses.

Crime: when you press the kickstarter lever, there is no resistance to compression of gases in the cylinder.
Analytics: the piston, cylinder, piston rings are extremely worn out.
Actions: check the compression - using a compression gauge or by measuring the parts (after dismantling the cylinder). Upon confirmation of the diagnosis, the engine requires repair with replacement of worn parts.

Crime: the sound of escaping gases is heard, oily traces are formed on the head and cylinder.
Analytics: the gasket under the cylinder head is damaged or the fastening of the head to the cylinder is loose.
Actions: replace the gasket and tighten the nuts securing the head to the cylinder with the required torque (effort) in the sequence recommended by the repair manual.

3) EXTRAORDINARY SOUNDS IN THE ENGINE
Analytics, version 1: increased wear of parts of the cylinder-piston group.
Action: the engine requires repair with replacement of worn parts.
Version 2: the thermal clearance in the valve drive is broken (for 4-stroke engines).
Action: adjust the valves.
Version 3: Loose chain in the valve drive (4-stroke engines).
Action: adjust the chain tension.
Version 4: grooves in the variator pulley have developed, along which the rollers move, as well as the rollers themselves.
Actions: replace the worn pulley, rollers (possibly other variator parts).

4. ENGINE STOPS AT SHARP OPENING OF THE THROTTLE
Circumstance 1: The engine has just started.
Analytics: the engine is not warm enough.
Action: continue warming up the engine at idle speed.

Circumstance 2: The engine is well warmed up.
Analytics version 1: carburetor not adjusted.
Actions: adjust idling speed, if necessary - the main dosing system (see item 5).
Version 2: the variator does not work properly.
Actions: see item 10.

5. THE ENGINE STARTS NORMALLY BUT IT DOESN'T SPIN
Crime: thick smoke in the exhaust, excessive fuel consumption, black plaque on the spark plug electrodes.
Analytics: The main dosing system prepares an overly rich mixture.
Actions: adjust the quality of the mixture - lower the carburetor throttle adjusting needle one notch (groove) down. It may be necessary to install a smaller bore main jet.

Crime: the engine overheats, detonation is heard during acceleration, white bloom on the electrodes and spark plug insulator. After turning off the ignition, the engine continues to run for a few seconds (detonates).
Analytics: The carburetor's main metering system is preparing an overly lean mixture.
Actions: adjust the quality of the mixture - raise the carburetor throttle adjusting needle one step up. It may be necessary to install a large bore main fuel jet.

Crime: the engine runs unusually quietly (although it is easy to start), low-smoke exhaust, the engine “does not pull” during acceleration.
Analytics: muffler, channels and cylinder windows clogged with carbon deposits (in two-stroke engines).
Action: clean carbon deposits if possible. If the muffler is completely clogged (no air flow), replace the muffler.

6. AFTER A LONG DRIVE, THE ENGINE LOSES POWER
Circumstance 1: an air-cooled engine.

Crime: no air movement is felt from under the cylinder casing, and a sheet of paper does not "stick" to the air intake mesh (on the right side of the engine) (if a test is carried out with paper).
Analytics: the fan impeller blades are broken, another assumption is that the shrouds of the cooling system are loose or split in places.
Procedure: Replace the impeller and damaged covers.

Circumstance 2: Liquid-cooled engine.
Crime: coolant leaks, its level in the tank has dropped.
Analytics: faulty components of the system: pump, thermostat, radiator.
Action: replace faulty components.

7. ENGINE DOES NOT ACCELERATE THE SCOOTER TO 50 KM / H
Inspection data: speedometer calibrated, no power or rev limiter installed.
Analytics version 1: The scooter is not designed for this speed.
Actions: all actions are meaningless.
Version 2: the carburetor is incorrectly adjusted, the muffler is clogged, or the parts of the cylinder-piston group are worn out.
Actions: see item 2 or change the scooter.
Version 3: the variator is not working properly.
Actions: see p. 9, 10.

8. WHILE THE ENGINE IS RUNNING, THE SCOOTER DOES NOT MOVE FROM THE PLACE.
Crime: the variator is faulty.
Analytics: the driven pulley spring is broken, the V-belt is torn (to make sure of this, remove the variator cover - breakdowns are perceived at a visual level).
Action: replace defective parts.

Crime: faulty centrifugal clutch.
Analytics: the springs of the shoes are broken, the linings of the shoes are excessively worn out (found out during a visual inspection after removing the variator cover) (photo 9). Action: replace defective parts.

9. THE SCOOTER RIDES IN SPECTS
Crime: jerks are felt when driving.
Analytics: the variator belt slips (due to wear, damage or oiling) or the surfaces of the pulleys are excessively worn out.
Action: replace defective parts (photo 10).

10. SCOOTER SPEEDS SLOWLY, RIDES SLOWLY
Analytics: in the course of a recently carried out tuning, the weight of the centrifugal regulator weights or the spring of the driven pulley were selected incorrectly. The springs of the centrifugal clutch shoes are broken or have lost their rigidity, the linings of the centrifugal clutch shoes are worn or oiled.
Actions: carry out the tuning more thoroughly, preferably with the participation of specialists.

The popularity of scooters is growing every year. And this is not surprising. Low cost, ease of maintenance, good performance make the moped an irreplaceable thing in the life of many.

In many countries of the world, the number of scooters on the streets exceeds the number of cars. They have high maneuverability, which allows residents of megacities not to think about traffic jams. However, sometimes situations arise that the moped breaks down and does not want to start.

You can repair the scooter yourself or take it to a workshop. This is everyone's personal decision. Having decided to repair it yourself, you need to prepare the space for this. Most often, repairs are carried out in the garage.

The most common malfunctions associated with changing oil and filters... Improperly selected oil can be the reason that the engine will not start.

First you need to drain the old oil through the drain hole. Then the carburetor is completely disassembled.

The device and repair of Chinese mopeds should not cause big problems for a person who understands at least a little about this.

In order to identify a scooter malfunction, it is necessary to check all the elements in turn. The performance of any scooter depends on the proper functioning of components such as compression, fuel and spark. If one of the elements does not work, the scooter will not run.

Fuel can cause the moped not to start if gasoline has been filled for a long time. Studies show that from a long stay in the tank, the octane number of gasoline decreases, that is, its quality deteriorates noticeably. There is only one result: a spark does not ignite such gasoline. If you know that you have been pouring fuel for a long time, it is best to Drain the old gasoline and fill in new one in its place.

The second reason that the scooter will not start may be a dirty filter - fuel or air. The fuel filter is necessary in order to purify gasoline from various impurities and rust. The engine must be supplied with clean gasoline, since the wear of many parts of the moped depends on it.

The air filter is designed to clean the air that enters the carburetor. It must be changed quite often, since dust, dirt, etc. constantly settle on it.

The third reason the engine won't start may be a lack of spark. Checking whether the candles are to blame for this is as easy as shelling pears. It is enough to replace them with new ones. If it was not possible to start, and the gasoline is filled with fresh gas, you need to look for the reasons deeper.

Having determined that neither candles nor gasoline are the cause of the malfunction, let's move on.

As noted earlier, engine performance problems can vary. Very often, these problems are associated with candles or with a carburetor. The spark may not skip due to carbon deposits on the candle, which occurs due to the use of a rich mixture.

There may be a small gap, which also does not contribute to a normal spark. In a two-stroke engine, this gap is 0.6-0.7 mm. With a smaller gap, there is a greater likelihood that the electrodes will melt. Increasing the gap causes the current consumption to increase and more voltage is required to generate a spark.

There are situations when the moped stalls while driving, and then continues to go further. This is due to the detachment of carbon deposits from the electrode. The spark is lost for a while and the engine stops working. After self-cleaning, performance is restored.

Interruptions in engine operation can be associated with moisture ingress on electrical appliances and wiring. This leads to a loss of voltage. After drying these parts, engine operation should be restored.

A fairly common reason in our climate is water entering the fuel and then into the carburetor.

The reasons considered are easily eliminated by the driver himself. However, if these actions did not bring the desired solution and the engine does not work, the scooter engine should be repaired.

With regard to the carburetor, the causes of malfunctions can be caused by inadequate mixture quality.If the mixture is poor or rich, the performance of the moped will be compromised. The quality of the mixture can be checked by the condition of the candle. Black color will indicate that the mixture is rich, that is, there is an overconsumption of oil. White color will indicate a poor mixture and a decrease in engine power for this reason.

Repair of the scooter carburetor is performed on a warm engine. Before that, if there is a possibility of clogging, it should be cleaned and rinsed. The carburetor adjustment itself consists of the following actions:

1 action - it is necessary to adjust the idle speed.

This action is performed using the idle screw. In order to increase the speed, the screw is tightened, and to decrease, it is unscrewed. After warming up the scooter, using simple manipulations, you can set up stable engine idling.

Step 2 - check and adjust the quality of the mixture for the carburetor using a special screw.

The combustible mixture that enters the carburetor must clearly have the proportions set by the scooter manufacturer. If the mixture is too lean, the scooter loses power and overheats. With a rich mixture, fuel is used uneconomically. This problem can be solved by turning the screw. Turning the screw clockwise enriches the mixture, counterclockwise depletes it. The color of the candle will indicate the quality of the mixture. The candle is black and soot, which means the mixture is rich. If, on the contrary, it is white, the mixture must be enriched.

3 action - set the quality of the mixture by moving the needle.

The following manipulations are performed with the needle: when the needle is raised, the mixture is enriched, and when the needle is lowered, it is depleted.

4 action - regulation of the fuel level in the float chamber.

Checking the fuel level is done with a transparent tube on the bottom of the carburetor. The procedure is as follows: unscrew the cream screw, lift the pipe up and check the fuel level. The fuel level is monitored with the engine running. The tube should be held above the carburetor. The fuel level should be slightly below the curb on the carburetor cover.

Repairing Chinese engines does not pose any particular difficulties for most scooter owners. It should be remembered that the main attachments of the "Chinese" are more delicate than in domestic mopeds, so you do not need to pull anything with all your might.

For example, sudden movements when repairing the carburetor of a Chinese scooter can cause the pipe will be damaged... Then the muffler is removed. Many Chinese scooter manufacturers use plastic soldering. This must be taken into account when parsing a moped.

Manufacturers have foreseen that many scooter owners will want to carry out repairs on their own, so there is simply nothing complicated in the design of such scooters. Chinese scooter repair manual will allow you to do all the steps yourself. Everyone will be able to deal with the main problems and repair the engine of a Chinese scooter.

A scooter repair video will answer most of your questions.

On scooters, a fairly common problem can be the occurrence of foreign noise. In this case, you can repair the scooter engine with your own hands. To do this, you need to understand how you can determine the cause of their occurrence and how you can deal with it.

Basically, the occurrence of foreign engine noise on a scooter can occur due to the wear of various parts. The motor in a scooter is subject to gradual wear, however, like almost all other mechanisms. Some parts are subjected to colossal loads during operation, which is why over time they can simply become unusable. It is necessary to understand in time that there are some problems with the engine, because due to the wear of one element, the performance indicators of others can significantly decrease.

Scooter engines have a much lower service life in contrast to automotive units. For this reason, the scooter owner must make timely diagnostics of the engine operation. And if suddenly some malfunctions appear, then do-it-yourself scooter engine repair is required.

When some parts of the engine wear out, a variety of sounds can occur during its operation, for example, chirping or light ringing. They can appear at high speeds, as well as at idle. In addition to noise, the scooter may lose the previous level of dynamics, experience some problems while driving, and also not reach high speed. If such problems appear, then you need to think about repairs. If the breakdowns are insignificant, then you can do it yourself with certain knowledge and tools.

If the power unit functions normally at idle, but howling occurs when a high speed is set, then the crankshaft bearing may well fail. Such parts cost relatively little, which is why it is not recommended to neglect their timely replacement. Better not to save in this case. If the scooter engine will be repaired independently, then you need to be as careful and calm as possible. During assembly and disassembly of the engine, the basic repair rules must be observed, that is, there is no need to rush. When new bearings are installed, it is also very important to keep clean, because just one grain of sand in the motor can have a serious negative impact. It will also not be superfluous to flush the old bearing in gasoline. This is necessary to remove the grease. If you cannot dismantle it yourself, then it is recommended not to risk it, since careless actions can cause damage to the crankshaft. But if everything went well, then the bearings need to be run in.

Another popular problem with an engine is piston wear. Rings can wear out rather quickly. If there are problems with starting the engine and at the same time a metallic ringing is heard, then the piston grooves are probably worn out. In this case, the piston must be replaced. It is important to do this in a timely manner.

In order for an internal combustion engine to work, it needs three components: fuel, spark, compression. The main slogan of the motor mechanic is “miracles do not happen”. It must always be remembered that if, when troubleshooting and scooter repair it turns out that there is a spark, there is compression, fuel comes in, but the engine does not start, this usually means only that some of these components are actually missing.

Too lazy to give the scooter for repair and pay money for it. Familiar situation. Then it's time to take on the repair with your own hands.

The basic principle of troubleshooting and repairing a scooter is to exclude system elements step by step, trying to identify the cause of a malfunction in one of them. Search and repair must be carried out strictly sequentially, from the very beginning of the chain to the very end. That is, for example, in the absence of a spark, you should not immediately change the switch. First, you need to make sure that we have a "live" generator, then test the wiring. Etc.

An important note: if you have a device in front of you, which, according to the owner, “used to work like a clock”, it makes sense to ask if old gasoline is poured into the tank. A couple or three months of storage is quite enough for gasoline to lose its octane number to such an extent that it has lost the ability to ignite.

It is important to remember that before making the final diagnosis and starting the repair of the scooter, you need to make sure that a working candle is installed on it, as well as the carburetor is functioning normally.

In addition, you need to know that the correct operation of the engine (even at idle) is closely tied to the correct operation of the variator, clutch, as well as the camshaft and valve group.In other words, with normally functioning power supply, ignition and CPG systems, the problem may be, for example, in the transmission, since the crankshaft torque is directly transmitted to the variator.

When carrying out diagnostics and repairs, it must be remembered that under some circumstances that led to the need scooter repair, it is necessary to check not a single element, but the entire system. For example, if the carburetor is clogged, provided that the air filter is intact and impregnated, it is necessary to check if there is any dirt in the gas tank and fuel filter. If the scooter has been driving for a long time without an air filter, or with an untreated filter, then everything must be checked: the CPG, the crankshaft and the main bearings.

Below are some of the problems that you may encounter and the basic steps to take to fix them. The links indicate the places where you can find information on this item.

Constant traffic jams create difficulties for car owners. The travel time increases significantly. As a result, drivers have to spend most of the day in their own vehicle. The metro is one of the options for solving this problem, but it is not acceptable for everyone. Therefore, some people prefer a scooter. But users have a question about whether it is possible to repair Chinese scooters with their own hands?

A scooter is a vehicle that allows you to reduce the duration of the trip to and from work. His owner has more free time to communicate with friends and relatives. Now you don't have to put off urgent business for the weekend. A maneuverable vehicle can save not only your time, but also nerve cells. Please note that a 150cc scooter engine is best suited for urban roads. It refers to units with an average power. Moreover, even this volume is enough to accelerate to 125 km / h. In addition, the engine for a 150 cc scooter requires only 3-4 liters per 100 km.

Efficiency, maneuverability - these are the main advantages of a scooter. On it you can get to the desired place much faster than by car.

This type of transport is not that expensive. The scooter is also suitable for country trips and you do not have to wait for public transport.

You can repair a Chinese scooter yourself. In addition, there are many offers on the market for the sale of all the necessary spare parts. Therefore, repairing Chinese scooters with your own hands does not present any particular difficulties.

Sometimes the wrong brand of oil is poured into the scooter. Prepare all the necessary tools.

The first step is to drain the oil from the oil system. After that, a complete disassembly is carried out. The carburetor removal operation seems difficult for a beginner. In order not to damage the special pipe, do not jerk the parts violently. First, we loosen the muffler mount, and then completely remove it. In many models of Chinese scooters, plastic soldering is widely used.

You need to find the filler and drain holes. It's good if you have instructions. But what about the rest of the owners?

The rear gearbox must be marked with the required amount of oil. There are plugs next to this inscription. The drain hole is located closer to the rear wheel mount of the scooter to the CVT. Moreover, the filler hole may look like a pipe sticking out of the variator or a simple bolt.

Then we proceed to unscrew the filler and drain nuts. We pour the used oil into a previously prepared container. Chips in the oil may indicate a dirty gearbox. Check the tightness of the gear cover gasket and the oil seal. If necessary, they will have to be planted on a gas-resistant sealant. There must be no oil in the gearbox. We tighten the drain plug.

After that, pour fresh oil into it. Usually the volume of oil is 100-200 ml.

How can you determine the cause of a malfunction?

To do this, you need to identify the elements that most likely led to its appearance. After that, check each of the elements sequentially.

The scooter's performance is dependent on 3 components: fuel, compression and spark. Therefore, if your scooter does not start, then it is imperative to check the performance of these components. The scooter repair is based on the principle of mutual exclusion.

Gasoline in the gas tank of a scooter loses its octane number during long-term storage. This results in no ignition of the mixture. Therefore, gasoline often requires replacement. A malfunctioning ignition system may be related to the condition of the spark plugs.

If the previous systems are in good working order, then the breakdown of the scooter may occur due to a malfunction of the carburetor. To check it, you must first check the fuel level in the system. Needle valve defects can also lead to problems when starting the scooter.

The scooter fuel filter is designed for fine cleaning of gasoline. Moreover, he must timely clean gasoline from rust, sediment and

other small particles. In addition, air is drawn into the carburetor. An air filter is used to clean it.

Distinguish between disposable and reusable gasoline filters. After a certain mileage, disposable filters must be replaced. They cannot be disassembled, cleaned or reused in the scooter.

Moreover, metal gas tanks have a significant drawback. During operation, particles of rust and old paint are formed in them. The main thing is to make sure that the filter does not get clogged with dirt and that a sufficient amount of gasoline can pass through.

1. We loosen the fastening clamps that are installed on the hoses.
2. Have you noticed damage on the highways? Place a dry cloth under the damaged area to prevent fuel spills.
3. The filter can then be removed.
4. The new filter is installed taking into account its direction.
5. The final stage of replacement is tightening the clamps.

As you can already understand, the repair of a Chinese scooter is no different from the usual. Well, if you are also a motorcycle enthusiast and have dealt with heavy sports motorcycles, then repairing a scooter will not give you any difficulties at all.