It happens that the scooter easily picks up maximum speed at first, but over time it picks up speed worse and worse. The maximum speed that the scooter can reach is also reduced. But it's not scary. You just need to determine the reason and return everything as it was. In this article we will talk about why a scooter does not pick up speed well. If you have a Chinese scooter of 50 cc, then check that you really have 50 cc. Often Chinese engineers install a piston engine not of 50 cubic meters but up to 80. This does not cost more and the scooter has better dynamics and maximum speed. But it happens that a Chinese scooter has 150cc, but it cannot accelerate more than 70 km/h. Such scooters are not supplied to Europe through strict controls, but successfully enter the countries of the former USSR.
Why does a scooter pick up speed poorly?
- Belt variator . It happens that over time the variator belt wears out. It is enough to wear down by 1-1.5 mm. and this can reduce both acceleration speed and top speed. Moreover, the maximum speed can be reduced by 20 km/h, just 1-2 mm of a worn variator belt. Therefore, it is worth checking the width of the belt sometimes. Ideally, the belt should be replaced when worn by 1 mm. And belt wear should not be allowed to exceed 1.5 mm.
- Variator rollers . If the variator rollers are worn out, this will also reduce the maximum speed. There are two reasons why the rollers can fail: – The rollers have worn out and become lighter in weight; – The shape of the roller has changed from round to triangular or quadrangular. In this case, you need to replace the variator rollers. To prevent this from happening, the rollers need to be changed on time. If you have cheap Chinese quality CVT rollers, then you need to check them every 4-5 thousand km. If you have original high-quality rollers, then you need to check them every 15-18 thousand km.
- Air filter . The reason that the scooter does not pick up speed well may be a clogged air filter. In this case, the maximum power of the scooter may drop significantly due to lack of air. Moreover, fuel consumption in a scooter increases, maximum speed and acceleration dynamics decrease.
- Piston . Wear of the scooter's piston can cause deterioration in dynamics and a decrease in the maximum speed of the scooter. You need to check the compression, it should be at least 7 atm.
- Silencer . A clogged muffler will not allow your scooter to accelerate up to 40 km/h (for 50cc). This usually only happens on two-stroke scooters.
- The reasons that the scooter does not reach maximum speed can also be: a dirty or incorrectly configured carburetor, poor quality gasoline and oil, worn bearings. There may also be such primitive reasons as heavy weight or driving against the wind. The increase in weight that the scooter carries affects the dynamics of acceleration and maximum speed.
Now you know why the scooter does not pick up speed well.
How to clean the muffler
Manually
With a metal cable, acting like a brush. Convenient, fast, but not for long.
Heat treatment
With a blowtorch or in an oven or barbecue (but then be sure to remove the muffler from the scooter). The muffler warms up as much as possible. With blows, the soot resulting from calcination is shed off, and it is blown out using a compressor. Effective, but the result will look unaesthetic.
Chemical treatment
Dismantle the muffler. Wash with pipe cleaner or other caustic liquid, such as sodium hydroxide. Rinse with clean water. Dry well. The end result is a very high quality one. But it’s long and difficult.
What to do if the variator belt is worn out
Both longitudinal and transverse cracks require replacement of the variator. Moreover, it is better not to delay it in order to avoid serious consequences.
Muffler cleaning
It is easy to replace the variator belt if you do not delay this procedure before the belt fails. If you tighten until the weights fall apart, you will most likely need to completely replace the entire mechanism. It’s cheaper and easier not to delay.
To change the belt, all you need is a gas wrench. But it will be difficult to completely replace the mechanism without special tools.
Possible reasons
First of all, you need to look for a breakdown in the scooter’s structure, but you also shouldn’t forget about other reasons, for example, external influences. The main breakdowns will be discussed below.
Belt variator
A variator is a device for increasing the speed of a scooter by using rollers of different diameters. The main element of this mechanism is a belt that transmits torque. It must be of a certain length, width and, most importantly, thickness. A slight wear of the belt by just 1 mm can change the overall radius of the belt loop, which leads to a drop in the maximum speed. It is clear that you cannot measure the thickness of the belt by eye; for this you will need a caliper. If the measurement shows a deviation from the norm by 1 or 1.5 mm, the belt should be replaced
There are several types of scooter breakdowns
CVT rollers
These elements of the gear shifting mechanism wear out over time. They become thinner or lose their correct geometry, for example, only one side of the roller wears off and it stops performing its functions. The repair is simple - replacing the worn out roller. There are two options for rollers - expensive high-quality and cheap. Knowledgeable people recommend buying cheap ones, since both of them are erased after about 3-5 thousand kilometers. Therefore, there is no point in overpaying.
Air filter
A visual inspection of the spark plug helps to understand that the reason is in this particular unit - it is covered with black deposits. It is also worth paying attention to increased fuel consumption, this also indicates a problem with the air filter. That is, the combustible mixture becomes enriched due to lack of air, hence the deposit on the spark plug and increased gasoline consumption.
Several parts in this unit may become unusable - sealing rings on the cylinder, cylinder walls, for example, due to scratches, chips on the piston. Piston problems are easily diagnosed by measuring compression. If it is less than 7 atmospheres, then you need to disassemble the engine. Repair depends on the degree of destruction of the piston, but in any case, it is necessary to replace all gaskets in the block, even if the repair consisted of replacing the O-ring.
The variator belt must be of a certain length
If it is clogged, then the engine power is sharply reduced. Repair consists of replacing the muffler or burning it. It is possible, in principle, to remove it completely, but then the roar of the engine will disturb the peace of the townspeople.
Dirty carburetor
This device is designed to prepare a combustible mixture consisting of gasoline and air, which are mixed in certain proportions. A carburetor is a rather complex device, having a lot of nozzles and jets. This is precisely how they can become clogged during operation with dust or small fractions floating in gasoline. The holes are so small that to clean it you will have to completely disassemble the carburetor and blow them out with a compressor, and the device itself must be thoroughly wiped with gasoline, both inside and out. If you don’t have a compressor at hand, you can try to clean the inside of the carburetor with a special compound, sold in auto stores in the form of aerosol cans.
Inspection procedure and repair methods
If the scooter does not travel more than 40 km. h., then there is a certain procedure for checking and searching for causes. Accordingly, for each reason there is its own algorithm for repair work.
There is a specific algorithm for repair work for each breakdown.
First of all, the spark plug is checked. To do this, you need to unscrew it and inspect it. If the contacts are clean, then everything is in order. If they are covered with black soot or, on the contrary, they are clean but have a red tint, then there is a problem with the mixture. Repair in this case consists of cleaning and servicing the carburetor.
Next, you can check the quality of the spark on the spark plug and, if it is weak, you need to check the contacts on the high-voltage coil, on the inductive ignition sensor and on the ignition switch. The presence of a short circuit in the specified components and breakdowns to the housing are also checked.
The next step is checking the engine. To start with its temperature. If it overheats, it could mean the mixture is too lean or the fuel is bad. This can be eliminated by cleaning the carburetor.
You can measure the compression at the nearest service station, and if it is low, you will have to disassemble the engine and look for a problem in the piston group.
Operating rules
Any manufacturer includes an instruction manual for their product. It describes when and how the scooter is serviced, how its correct operation is checked (ignition, gear shifting, engine compression and exhaust systems). If the scooter does not pick up speed, then this is primarily due to violation of these instructions. That is, you need to regularly change spark plugs, belts, oil, air filter, and monitor the quality of gasoline and oil. It is necessary to clean the contacts of the electrical system and change the battery on time. Maintenance is not only wiping the scooter from dust, but an in-depth diagnosis of all its components and mechanisms.
The scooter does not move after warming up
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Hello! I don’t know who to contact at all, so I’ll ask here. The topic is generally completely offtopic, but maybe someone can help.
Last year I bought a Suzuki ZZ Inch Up Sport scooter, 2 stroke, 50 cc. I drove it all summer. At first it seemed to drive normally, but over time it started to drive worse and worse. On the long hill at the end of last season, at the very end of the climb, I was driving at a speed of no more than 20 km/h. I sent it in for repairs: they cleaned the carburetor, replaced the piston, bearings and crankshaft seals with original new ones. But the problem remains. I can practically hold the scooter when starting off with my feet at maximum throttle. Maximum speed = 55 km/h, more is the cutoff. The maximum speed should be 60 km/h, but the variator belt is worn out.
The guy who repaired it for me repairs scooters, chainsaws, gas trimmers and other similar equipment. But he doesn't know what the problem might be. He has a Suzuki Address 110 scooter and he says that with him it behaves exactly the same after warming up, but there the volume is 2 times larger and it doesn’t feel that way. Today I went to see him, he called a man with the same scooter and swapped: - a switch, - an exhaust pipe, - a variator with a torque driver.
Motorcyclist
The most common reason is a worn clutch, then a worn variator belt, worn variator rollers, a worn clutch spring, and the variator itself can also be worn out. The most dangerous thing is examining and replacing the variator. On most scooters, the nut that secures the CVT is unscrewed clockwise; Do not unscrew it with a bolt gun under any circumstances, because you can break the crankshaft thread (then you get a lot of money: crankshaft from 3000 rubles + work to replace it with engine overhaul)
There are, but less frequently, other causes of breakdowns. In the event of such a breakdown, getting into the engine is the last thing; at least first measure the pressure in the cylinder with a compression gauge (at the same time check the spark plug). It happens that the carburetor is clogged, as well as the exhaust pipe (in the latter case, a scooter that accelerates to 60 km/h has difficulty accelerating to a maximum of 20 km/h). As for a clogged exhaust pipe, either the pipe is replaced, or the removed pipe is placed in a fire, heated, and then the soot is shaken out of it. Another method is possible (if you know a welder): a thick part of the pipe is sawed with a grinder (lengthwise), the soot is shaken out, then the pipe is welded.
Why does a scooter ride poorly?
If the scooter, immediately after purchase, easily squeezed out its required 60 kilometers per hour (we are talking about fifty dollars), and over time began to gradually slow down at maximum speed, do not panic. Sometimes it is enough to determine the reason for this behavior of the scooter and return everything to its place within a few minutes.
It should be noted that some Chinese pseudo-fifty dollars, while new, can easily accelerate to 70 km/h or more. Pseudo-, because usually there are not 49.9 cubes at all, but from 62 to 82cc. This is a deliberate step by Chinese engineers. Installing a larger piston does not entail any monetary costs, but it has a noticeable effect on both the dynamics and the maximum speed. Such scooters are not supplied to Europe, since there is strict control over both quality and compliance with all basic environmental and cubic capacity standards.
But in the post-Soviet countries they are in great demand due to their low price, large size and pleasant appearance (not always).
Chinese cubic scooters also have sufficient demand that the reason for the decline in maximum speed affects them too. Sometimes it happens that a Chinese scooter with an engine capacity of 150 cubic centimeters cannot accelerate more than 60-70 km/h. These are unacceptable indicators that definitely need to be understood and corrected, which is what we will do next.
So, the main reasons that entail a decrease in maximum speed, and sometimes dynamics:
1) The variator belt has worn out by more than 1-1.5 mm , after which it cannot reach the maximum radius of the variator, and therefore there can be no talk of maximum speed.
To understand this, take a look at the picture below.
The left cheek denotes the variator itself, the right cheek the clutch. The position of the belt and rollers during all operating ranges of the scooter are indicated on the side.
We are interested in the highest gear, in which the variator belt should be as close as possible to the edge of the cheeks.
If its width is below the permissible standards, it cannot do this, hence the maximum speed drops, sometimes up to 15 km per hour less than the norm (if the belt is heavily worn). Therefore, it is important to periodically check the width of the belt with a caliper, and if it is worn down to 1.5 mm (ideally 1 mm), replace it with a new one. You can find all factory sizes of scooter belts on our website.
2) Wear of the variator rollers on a scooter also entails a decrease in maximum speed. There are two factors here - a reduction in the weight of the roller itself and a change in shape from round to square (triangular, it doesn’t matter), when the roller does not roll out in the ditch, but simply slides in it.
Here are photos of worn-out rollers, which should not be allowed:
NEXT comparison with new videos
To avoid such situations, check the rollers for wear every 3-4 thousand km. Some will say that they should last much longer, but this only applies to high-quality and branded spare parts made from durable material. They cost 5-6 times more than regular Chinese ones, and they cost about the same amount of time. My opinion is that it is better to periodically change cheap rollers for $5 than to buy branded ones for $30. However, for serious tuning, it is still better to pay attention to quality.
3) Piston wear on a scooter is one of the most important factors in which both maximum speed and dynamics are reduced. The engine simply loses power and cannot realize its original performance. At the same time, the compression reading plays a key role in determining piston wear. It can be measured with a regular automobile compression meter at any service station. If these indicators are less than 7 Atm, the piston and rings on the scooter engine must be replaced. In this case, it is better to immediately clean the windows in the cylinder from carbon deposits, as well as the inside of the cylinder head. Remove the old gaskets under the cylinder and head and replace them with new ones. Take the replacement of the CPG seriously, install the rings and the direction of the locks correctly.
It is important to undergo proper break-in and not overheat the scooter engine. When the parts of the cylinder-piston group are not yet ground in well enough, any loads can lead to overheating.
4) A clogged air filter on a scooter significantly reduces engine power as it lacks air. At the same time, the mixture is enriched, there is no overheating. By constantly driving with a rich mixture, the period of soot formation in the engine is reduced. In addition, fuel consumption increases, dynamics and maximum speed decrease. There is a black velvety coating on the spark plug electrodes.
5) A clogged muffler on a scooter (usually only on two-stroke scooters) greatly reduces engine performance; often the scooter cannot accelerate more than 30 - 40 kilometers per hour. This disgrace is cured by burning out the muffler. I won’t describe the whole process; we’ve already looked at it.
6) A dirty carburetor on a scooter (from the inside, of course) cannot properly supply fuel to the combustion chamber, and also cannot prepare the mixture in the given proportions. In such conditions, achieving maximum speed on a scooter is doubtful. To fix the problem, you need to remove the carburetor, then remove the float chamber cover, remove the float and shut-off needle. After this, you need to thoroughly rinse and blow through all the carburetor channels. You can use gasoline and a compressor, but not everyone has such an expensive thing as a compressor at hand.
CONTROL ON THE ROAD
It’s one thing to master the skills of driving a scooter in an empty area, and quite another to join the hustle and bustle of city streets
Need I remind you that while driving, all your attention should be focused on what is happening around you? If all you are doing is trying to control how you maintain your balance, including when turning, then it’s too early to hit the road.
Riders of 50cc scooters have few legal options for positioning on the roadway. They are instructed to drive in the far right lane, as close to the sidewalk or curb as possible. In life it’s different: you have to drive closer to the middle in order, say, to go around potholes or foreign objects... Blindly following traffic regulations and driving at the very edge is dangerous. What if a pedestrian takes a step off the sidewalk? Or will a careless car owner open the door of his car?.. It’s safe to stay in the middle of the right lane or even a little to the left.
You should not trail along in the same lane with a slowly moving truck or bus. And it’s better not to approach them: it gets boring quickly. In addition, it is so easy to miss an open hatch or brick that your “leader” missed between the wheels.
The difficulty of driving through city intersections is not even heavy traffic, in which it is difficult to maneuver. Multi-level interchanges in modern cities, tricky lane layouts, prohibitory traffic light signs - all this baffles even an experienced driver. Learn by heart difficult sections of the route on frequently repeated routes, master the algorithms for driving through intersections and junctions.
Law-abiding scooter riders are required to remember the restrictions prescribed for them (the main one is the prohibition of left turns on a multi-lane street). Let's hope that the outdated rules will be rewritten to take into account the increased capabilities of scooters, but until then, let accumulated experience and common sense become guides and good advisers when riding.
