Atlant scooter 50 cubes DIY repair

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 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 above reasons 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.

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.
Actions: 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. 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 carburetor on a scooter is an important part of the engine's power system and is responsible for supplying fuel to the engine's cylinders. But due to the wear of the parts, over time, your carburetor may need to be repaired.

In this article, we will tell you how to repair the carburetor of a scooter with a 2-stroke and 4-stroke engine with a volume of 50 and 150 cubic meters, and also explain how to install and adjust a new carburetor on a scooter.
The content of the article:

• Removing and cleaning the carburetor;
• Installing the carburetor;
• Adjustment (tuning) of the carburetor;
• Repair video;
• Our production;

In order to remove the carburetor from the scooter, the first step is to remove all the plastic that prevents access to the carburetor (usually you have to remove the seat and the plastic under the seat). Then we disconnect the fuel and oil hoses (there are oil hoses only on a 2-stroke scooter), the contacts of the starting enricher. After that, we unscrew the bolts securing the carburetor to the engine.

Now, after the carburetor has been removed, it is necessary to clean its outer surface from dirt and dust. Can be washed in gasoline and wiped off with a dry cloth.

The next step is to partially disassemble the carburetor, namely: unscrew the bolts securing the float chamber cover (2 bolts), then carefully remove the float so as not to bend the plate. We wash the float chamber cover itself very carefully from the inside. Now you can start cleaning the inside of the scooter carburetor itself.

2 easy ways to clean your carburetor:

1) We wash it in gasoline, then we purge using a compressor with a nozzle in the form of a pointed tip (this will effectively purge all channels).

2) We buy a can with a liquid for cleaning the carburetor. Thoroughly clean all channels and nozzles of the carburetor. Balonchik also replaces the compressor, since the liquid is supplied from it under high pressure, which makes it possible to effectively clean the small channels.

When cleaning, special attention must be paid to all channels and jets (unscrew the jets during cleaning). We also remove the starting concentrator and clean its channels. It is not necessary to dry the inside of the carburetor. Now we can put on the float and assemble the carburetor in the reverse order.

We install the carburetor on the scooter in the following sequence:

• 1) We fix the carburetor in the place of attachment with the engine, put on the air pipe and secure it with a clamp.
• 2) We put on the drain hose on the fitting (the lower part of the float chamber)
• 3) Install the throttle cable in a special bracket. We check that the protrusion on the cable fastening screw coincides with the groove on the bracket. We fix the cable with nuts
• 4) We put on the gasoline hose and secure it with a spring clamp.
• 5) Connect the contacts of the starting enrichment.

As you can see, the connection diagram for the carburetor on a scooter is not that complicated. Next, you need to adjust the carburetor.

Adjusting the carburetor on a scooter consists of several steps, which include: adjusting the idle speed, adjusting the mixture quality and adjusting the fuel level in the float chamber.

The carburetor setting of a 2t and 4t scooter has no fundamental differences, except that on some carburetor models there may be no screw for adjusting the quality of the mixture and therefore the quality of the mixture has to be adjusted only by adjusting the needle and float in the carburetor of the scooter

It is necessary to adjust the idle speed on the scooter engine warmed up for 12-15 minutes. The adjustment is carried out using an idle screw, which is installed on each scooter and which allows the engine to run smoothly at idle speed. When the screw is tightened clockwise, the revolutions increase, when unscrewed, it decreases. We warm up the scooter and achieve stable engine idling by adjusting the screw.

5 - idle screw on a 4-stroke scooter

The quality of the mixture is very important when adjusting the carburetor, because with a lean mixture, the engine can overheat and lose power, and with a rich mixture, carbon deposits form in the combustion chamber.

We adjust the quality of the mixture using the adjusting screw. The mixture is enriched if we turn the screw clockwise and depleted when we turn it counterclockwise.

The adjustment scheme looks like this:

• We warm up the scooter for 10 minutes, turn off the engine;
• We tighten the screw clockwise to the end;
• Unscrew 1.5 turns back counterclockwise
• We start the engine and turn the propeller back another 1/3 turn. Let the engine run for 2 minutes.
• If the revolutions increase, then unscrew the screw another 1/4 turn counterclockwise. We also let the engine run for 2 minutes.
• We repeat the previous step until the rpm starts to drop (do not forget to let the engine run for 2 minutes before each change)
• If the revolutions began to fall, then turn the screw clockwise by 1/4 turn.

Thus, stable operation of the engine is achieved at any permissible speed. Ideally, the engine should work well in the unscrewed position of the screw for adjusting the mixture quality by 1.5 - 2 turns. However, due to wear of engine parts, this range may change.

If the carburetor of your scooter does not have a screw for adjusting the quality of the mixture, then the adjustment should be carried out only by adjusting the position of the carburetor needle. Raise the needle - the mixture is enriched, lower the needle - the mixture is leaner.

By the soot on the candle, you can find out about the incorrect adjustment of the quality of the mixture. If the carbon deposits on the candle are black and there is a lot of it, the mixture is too rich. If the carbon is almost white, the mixture is too white.

The fuel level in the float chamber can be checked with a transparent tube on the bottom of the carburetor. In order for this to be possible, it is necessary to unscrew the cream screw, lift the tube towards the top of the carburetor. Now we check the fuel level with the scooter engine running. It should be located just below the protruding skirt where the float chamber cover is attached to the carburetor.

If the level is low or, as is often the case, too high, then it is necessary to remove the cover and adjust the moment of triggering of the locking game by bending the needle holder (small tendril) in a very small range.

It is worth remembering that if the carburetor malfunctions or its internal elements are dirty, adjusting the carburetor may only temporarily solve the problem.

That's the whole principle of tuning the carburetor on a Chinese and Japanese (Honda, Suzuki, Yamaha, etc.) scooter. Now you can independently repair and adjust the carburetor on a 2t and 4t scooter engine with a volume of 50 and 150 cubic meters.