Hi all. Every owner of gasoline equipment has encountered (or will encounter in the future) a problem - cylinder wear. Here they do everything they can - either buy a new cylinder and piston, or buy a new piston and go to a turner. Grandmas pay him, but he is bored... Many turners love blue (alcohol) and the straightforwardness of some leaves much to be desired... I suggest boring the cylinder yourself! It's pretty simple.
General provisions and safety precautions:
The author is not responsible for injuries, accidents during repetition, for “jambs” and defects obtained when trying to repeat the contents of this article.
- If you are under 16 years old, work should be carried out with adults (preferably a male assistant).
- Remember, you are working with rotating parts, do not wear gloves! Work with bare hands. There should be no sleeves on work clothes. Even if there is, roll up your sleeves to at least the elbow.
- What is in the photographs is the author’s work process.
- ANY cylinder can be sharpened using THIS method. The first one that came to hand was taken.
- For the sake of writing this article, a cylinder from the D-6 engine was taken.
- For boring you will need a drill with a power of at least 350 watts. In this article I used a 1050 watt drill.
- The lower the speed, the better. I have 550 rpm.
Please remember that you are working with electrical appliances. Do not allow exposed wires or other defects in the cable network. It is advisable to carry out work outdoors. If the workshop allows it, then you can do it there.
I hope everyone has checked the wires, the condition of the sockets, their workplace, and are ready to continue.
The principle of boring: a guide must pass along the entire length of the cylinder - also known as a “mill” (shaft, cylindrical body). It should be a perfect cylindrical shape. BUT it must be smaller than the current piston that was on the engine. “Rolling” sandpaper onto this shaft will give us a certain “grip” of grinding the metal. That is, the longer the blade, the more the cylinder “eats” from us. Exactly what is needed! To attach the paper to the shaft, we need to make a groove. And fix our sanding cloth in it.
When do you need to adjust the clutch of an Alpha moped?
When using the Alpha scooter, the rider may experience clutch slipping or slipping. In the first case, after starting the engine and switching to first gear, the bike starts moving (with the clutch held). But when towing, the moped refuses to move at all or does not pick up speed (although the speed increases).
The cause of such problems is simple wear of system parts or incorrect clutch adjustment on Alpha 110, 125 or 50 cc. see. Also, problems can arise if the bike is idle for a long time. For example, after wintering, a moped may start, but will not move. This problem usually occurs because the friction disc is stuck to the flywheel and discs. This leads to the fact that the bike does not “release” the clutch and refuses to move. And only complete disassembly and maintenance of the unit will solve such a malfunction.
Ignition system
The standard Minsk ignition system does not always successfully cope with its tasks. Therefore, it makes sense to carry out the revision carefully and carefully. Just like with Izh Planet 5 tuning, here they primarily work with the ignition timing.
The model has a good generator, as well as contactless ignition with an electronic switch. But, there is no possibility to change the advance angle depending on the operating mode of the moped engine. Therefore, it is recommended to install a device that forms the angle depending on the need at a given time.
How to adjust the clutch on an Alpha?
It is important to note that the clutch is located inside the engine. But even a novice driver can handle setting it up, replacing or repairing it.
To adjust the clutch of an Alpha 110 moped or any other similar bike you need:
- Place the scooter on the center stand.
- Remove the chrome engine cover (right side).
- Remove the two screws that hold the plate in place. This will give access to the adjuster and locknut.
- Loosen the nut and use a slotted screwdriver to slightly unscrew the screw. The shift plate must move freely.
- Remove the component, lubricate it and install it back.
- Tighten the adjuster until it stops using a slotted screwdriver (do not over-tighten).
- Secure the locknut so that it does not turn.
- Tighten the bolt on the clutch cable.
- Start the engine and engage first gear. It is important that the scooter remains on the stand as the rear wheel should not touch the ground.
- Hold the clutch and try to stop the spinning wheel with your foot. If it stops, then the Alpha clutch adjustment is complete.
If the wheel continues to rotate, the rider should tighten the adjusting screw 0.25-0.5 turns. The procedure is carried out until the wheel can be stopped. After making the adjustment, you need to tighten the locknut and install the chrome cover. At the last stage, the motorcyclist needs to adjust the bolt on the cable so that the handle stroke is 10 mm.
Some information about management
Driving the scooter is very easy. You just need to know what is and where it is. On the right side there is a front brake lever, and on the left, respectively, a rear brake lever. There are also other elements on the dashboard.
On the right side there is a steering wheel handle. They use it to gas. To do this, you need to rotate it. There are also various kinds of switches, such as turn signals and lights. Here, among other things, you can see the starter and horn button.
How to replace the clutch on an Alpha 110, 125 or 50 cc. cm?
Since the design of all small-capacity scooters is identical, these instructions are suitable for all two-wheelers. If the rider needs to change the clutch, he needs to:
- Remove the cap from the spark plug.
- Disconnect the cable from the gearshift foot.
- Remove the chrome cover, behind which there is an adjusting screw.
- Unscrew the bolts holding the engine cover and remove it. When performing the procedure, it is advisable to loosen the brake foot so that it does not interfere.
- Take out the bushings.
- Remove the clutch cover.
- Bend back the lock washer.
- Unscrew the central nut.
- Remove the clutch itself and install a new component.
After replacing the unit, you should readjust the clutch of the Alpha moped.
Note: When installing a new component, it is recommended to lubricate it immediately to avoid seizing and excessive wear of the discs. In parallel with replacing the clutch of an Alpha 110 or 125 cc moped, it is recommended to change the oil filter.
If a motorist can replace the unit independently, then it is advisable to entrust complete disassembly and repair of the element to specialists. Dvako Moto specialists have the necessary equipment to diagnose and service all scooter components.
Source
Motorcycle tuning Minsk
Minsk was perhaps the most widespread and accessible of the motorcycles of the Soviet Union. Produced at the Minsk plant, it enjoyed deserved popularity among motorsports enthusiasts and ordinary citizens for its low price, ease of operation and good maintainability. This unpretentious motorcycle could serve as both the first vehicle for a novice motorcyclist and a workhorse for many residents of cities and rural areas.
The ancestor of the Minsk motorcycle was the motorcycle of the German DKW center, the equipment for the production of which was exported from Germany as reparations in 1945. The production of the first models was established in Moscow, but then by 1951 production facilities were transferred to Minsk. The first motorcycle rolled off the assembly line of the Minsk Motorcycle and Bicycle Plant back in 1951. For more than 60 years of production of motorcycles of this brand, more than 6.5 million Minsk motorcycles have been sold worldwide.
Tuned motorcycle Minsk 125
But this mass-produced motorcycle, like any other equipment, of course, has its certain drawbacks. The main ones include:
But this amazing motorcycle provides its enthusiastic owners with ample opportunities to implement tuning ideas. And, although in the basic version, even with the most powerful engine, the Minsk motorcycle could hardly accelerate to 100 km/h, as a result of competently and responsibly carried out tuning from this beloved, but still not very technically advanced product of the Minsk plant, it is possible to make a truly nimble, responsive and fast motorcycle, not much inferior to its expensive foreign counterparts.
When to adjust the clutch
In general, there are two cases when you need to think about adjusting the scooter clutch:
Clutch leads
When you press the clutch lever and engage the gear, the moped starts moving (with the clutch depressed).
The clutch is slipping
When the gear is engaged and the clutch lever is completely released, the engine runs at high speeds, and the moped moves slowly or hardly moves at all.
All these problems are the result of a less than ideal design of the clutch release and engagement drive, as well as the fact that the parts of the clutch itself wear out after some mileage, which together leads to such troubles.
Let's start tuning a Minsk motorcycle with our own hands
To increase power we will tune the engine, clutch, ignition system, cooling and exhaust.
Engine tuning in Minsk - adding a few horses
The most powerful engine in the base, as mentioned above, is a maximum of 13 horses. Of course, this is completely insufficient for modern dynamic riding, motocross, and stunt riding (depending on what the motorcycle tuning is for). Modifying the Minsk engine is not very difficult. To increase power, you will have to work on the cylinder and piston of the motorcycle engine. We reduce the combustion chamber by grinding. This increases the compression ratio and engine power. The engine is now suitable for using high-octane gasoline and this will have a positive effect on increasing power.
Motorcycle engine Minsk
So let's get started:
Tuning Minsk for sports Such tuning of the engine of this motorcycle will allow you to add several horsepower to the power , which will immediately noticeably affect the dynamics and acceleration speed. The increased power as a result of engine modification will require replacing the standard crankshaft bearings with more durable ones. For this, it is best to use imported bearings produced by the Japanese company NTM.
Photos of tuning the Minsk 125 motorcycle
Reworking the ignition system
The standard ignition system with a very powerful and reliable generator, a contactless ignition system and an electronic switch require modification in terms of additional installation of a device to change the degree of ignition angle advance depending on the engine speed. With the help of such tuning, the Minsk motorcycle engine will run more smoothly and quietly, and its service life will increase significantly.
Motorcycle tuning Minsk
Exhaust tuning for a Minsk motorcycle
How to make a Minsk motorcycle quieter? To improve the power performance of this engine, it is very important to install a resonator in the exhaust system. A resonator is an oscillatory system where vibration energy is accumulated due to resonance with the driving force. A properly selected resonator allows you to ensure that some of the lost working mixture is returned to the cylinder by the time the exhaust window is closed. It is very difficult to find such a device for free sale, because... it was produced in limited quantities and only for cross-country versions of the Minsk motorcycle. But you can make it yourself using drawings available on the Internet.
Tuning the exhaust system on a motorcycle Minsk Tuning a motorcycle Minsk
Cooling system tuning
Increased power as a result of engine tuning will require a more efficient cooling system. It is necessary to purchase and install a more serious radiator.
Clutch modification in Minsk
Now, after engine tuning, the standard clutch will not be able to cope with the increased power in all operating modes of the motorcycle engine. It needs to be improved by replacing springs and discs. It is necessary to cut off a few millimeters of steel from the standard clutch discs and insert three more selected discs into the free space. As a result of this replacement, the clutch will become slightly stiffer in first gear, but overall the motorcycle will gain more dynamics and drive.
Now we can replace the rear wheel sprocket with a similar one, but with fewer teeth, which will add dynamics to the acceleration of the motorcycle. We replace the standard brakes with good disc brakes - do not forget about driving safety. All these measures, if carried out correctly and responsibly, will allow you to increase the power of a 125 cc motorcycle engine from the standard 13 to 20-23 horsepower, which of course will make your iron horse much faster and more interesting. A technically savvy owner can do the tuning of a Minsk motorcycle engine on his own, or you can contact a motorcycle center, where all the necessary work will be carried out not only quickly and efficiently, but also where you can quickly purchase all the parts and elements necessary for tuning a motorcycle.
Engine Features
The engine of the Chinese Alpha moped has characteristic features, thanks to which fans of motorcycle technology prefer this particular model.
Engine capacity - 72 cc. With the right approach, it can be upgraded to 110 cc. Also, if desired, you can increase the speed by 10 kilometers.
The weak point of the engine is the gearbox, which requires close attention and a delicate approach . When repairing the “heart” of a moped, you need to know how to correctly disassemble and reassemble this part of the motorcycle “organism”.
Alpha is equipped with a powerful engine, the circuit of which is complex. If you can’t figure it out on your own, it is recommended to contact an experienced specialist. The price of repairs is quite affordable.
Why won't my scooter start with the button?
This situation is also common. If the scooter starts with the kickstarter instead of the button, then the problem is in the main fuse. It is located in the battery compartment. To check its serviceability you need a multimeter.
This device should be set to DC voltage measurement mode. Note the voltage results before and after the fuse. It must remain unchanged. If it drops or increases by a few volts, the fuse will need to be replaced.
The problem may not only be this, but also the engine starting circuit. Here the integrity of the connecting wiring is compromised. In order to deal with this type of problem, you will need an electrical diagram of this circuit. In addition, you need to be able to read it correctly. Therefore, in this case, you should contact an experienced specialist.
Causes of malfunction
The Chinese Alpha moped, whose price is affordable, does not cause owners many problems. Interruptions in a moped engine have several causes, and once you understand them, you can quickly fix the breakdown.
Disassembling the moped engine
So, if the engine starts with great difficulty, the muffler “shoots”, and smoke comes out of the chimney, it means that the moped is “capricious” due to problems with the carburetor. In order to solve this problem with the Alpha moped, you need to:
- clean the carburetor;
- thoroughly clean the moped's air filter;
- tighten the screws;
- adjust the moped carburetor.
If the Alpha slowly picks up speed, and its engine is not able to develop the declared power, then the reason is the incorrect operation of the moped valves. It can also “get sick” due to gaps and incorrect timing. In order to make the Alpha moped function normally, it is necessary to replace the used valves with new ones.
If the Alpha moped is not able to reach the required speed, despite the roar of the engine and solid revolutions, it is impossible to stop the spinning wheel, and gear shifting occurs intermittently, then the cause of the malfunction is clutch wear.
To eliminate the breakdown, you must perform the following manipulations:
- remove the engine;
- remove the plastic cover;
- unscrew the tightening screw;
- Unscrew the adjustment mechanism and tighten the screw tightly;
- start a moped;
- turn on first gear and drive a few meters.
Another cause of moped engine malfunction may be wear on the drive sprockets. If they are very worn, they must be replaced with new ones.
You may encounter the problem of engine overheating. The situation can be corrected after adding oil. If oil leaks, you must urgently contact a professional service .
Alpha moped engine overheating
Engine disassembly
Disassembling the Alpha engine is quite simple. To do this you need:
- “arm yourself” with a key;
- Unscrew the bolts on the intake manifold (by 10);
- unscrew the cylinder covers and the bolts located there (4 pieces);
- remove the cylinder head.
After performing the necessary manipulations, you need to properly assemble the engine, installing all the parts in place.
A diagram can help you understand the nuances. Also, a lot of useful tips regarding repairing the most important “organ” of the Alpha moped are contained in the training video.
Consequences of untimely replacement
If you don't change your air filter, at best its performance will deteriorate over time. The moped will lose power and stop idling. Also, dust getting into the carburetor will clog all the channels, which will lead to unstable operation. The worst case scenario may be that dirt gets into the engine itself. Large particles will leave deep scratches on the cylinder bore and on the piston. The valve assembly may fail. Accordingly, a major overhaul of the engine will be required, so you should not neglect replacing the air filter. The consequences can be dire.
The frequency of replacement depends on the level of road pollution in the area. The cleaning system should be carefully inspected periodically.
Gearbox disassembly
It is necessary to disassemble the gearbox in order to replace used parts. This is done after the following parts have been dismantled:
Repair of this part of the engine is carried out as follows:
- Using a screwdriver or blade, remove the retaining ring and the drive gear;
- Carefully unscrew the gear fixing bolt and remove the gear shift mechanism;
- remove the gear shift fork and shaft;
- remove the crankshaft and drum (including the core);
- After replacing the worn part with a new one, reassemble (in reverse order).
Generator rotor puller.
A generator puller, or rather its rotor, will help remove the rotor from the crankshaft cone of any scooter without damage. It becomes necessary to remove the generator rotor, for example, before replacing the crankshaft oil seal, or to repair the engine (removing the crankshaft), as well as to remove the stator if its winding is damaged, or to replace the pulse sensor (Hall sensor). This article, more aimed at beginner scooterists, will describe how and with what help to remove the rotor of a scooter generator without damaging the parts, and will also show a couple of homemade options for a generator puller.
First, the generator pullers will be described, and below, for beginner scooter riders, the process of removing the generator rotor from the crankshaft conical axle will be described.
Factory generator rotor puller.
So, first I would like to write a few words about the factory pullers, one of which is shown in the photo on the left. Such a generator rotor puller can be purchased on the market or in specialized stores. Of course, it’s easier to buy a factory puller than to bother with its manufacture. Only now it is quite possible to run into raw products made from low-quality steel, which will not last long (the threads will quickly wear out).
A high-quality puller made of hard carbon steel is anyway more expensive, and if you see several options on the market, do not take the cheaper one, most likely it is made of the cheapest and softest steel - steel 2 or st3.
By the way, you can take a needle file with you, which will help you compare the hardness of the steel - carbon steel (for example, st45 or 50) is, of course, much more difficult to process with a needle file than steel 3.
What else should you pay attention to when buying a factory puller? You should remove the cooling impeller (more on this below) and use a caliper to measure the internal diameter of the thread in the generator rotor, which is intended for screwing in the puller. Of course, the diameter of the internal threads in the rotor must be the same as the external diameter on the puller you buy. As for the thread pitch, you can’t go wrong here; all pullers have the same fine thread with a pitch of 1.
Well, one more piece of advice: if you think that you will soon buy yourself another scooter (of a different model) or are going to repair scooters, then look for a generator puller that has two different threads in outer diameter on each side of the body.
Alternator puller with two different threads
Removing the rotor
Insert the bolts into the required holes. We take the bolts from the cooling impeller - they fit there perfectly. In order not to touch the windings, we screw restrictive nuts onto the bolts - they will not allow the bolts to go deep inside the generator.
We apply the puller to the rotor and screw the bolts into the holes. In order not to break the thread, slightly tighten the central bolt and see if all the bolts are tight. If any bolt is loose, tighten it.
This way we will evenly distribute the load between the bolts. If you neglect this moment, the entire load, unnoticed by you, can rest on only one bolt or two, and then they will break out of the rotor along with the thread. We don't need this, of course.
Now the main thing: what is there, you cannot tighten the central bolt by force. In this case, excessive force will not achieve anything. Everything must be done slowly and competently. Otherwise, you will tear the puller out of the rotor along with the roots, and then your budget will become completely financially insolvent.
You only need to remove the rotor this way: Lightly tighten the central bolt of the puller with a wrench, lightly hit the end of the central bolt with a small hammer - the rotor, usually, after the first blow, flies off the cone without talking, if it doesn’t fly off, pull the bolt again and hit again.
I learned this technique back in 1996, when I had the opportunity to remove the reel drive pulley of the Kolos combine harvester from the shaft. If it weren’t for one smart person who promptly told me how to work with a puller correctly, then I would have smashed both the pulley and the puller and the sledgehammer along with the combine...
The rotor sits on a key. If you do not plan to further disassemble the engine, leave it as is. And if you plan, you better get it, otherwise you’ll lose it.
A broken key can be easily removed with small pliers; if the key fits very tightly, leave it, it won’t get away from you.
So that you don’t have to guess later how your stator was positioned, we put marks with a core or take a photo, remember it, or do something else. This is necessary in order to protect yourself from problems with a lost outline.
It happens that when installing it back, the stator is installed in reverse, and then depending on your luck: everything may go without consequences, or the spark may disappear or interruptions may appear. To avoid this, any, not just CDI-type scooter generators must be installed exactly as they were originally installed. If you follow this golden rule, you will be happy.
We remove the stator. Installation of the generator is carried out in reverse order.
Crankshaft restoration
Due to the fact that recently the vast majority of people have begun to look towards Chinese scooters, their number has increased. As you know, the quality is not at the highest level, but it is quite acceptable for trouble-free operation for 2-3 years or even more. I don’t want to write about factory scooters, because their quality is high (they keep the brand), but not all of them.
In general, this article is intended for all scooter riders without exception and does not have clear boundaries in the brand and year of manufacture of the scooter. We will consider the KShM - the crank mechanism of a 2-stroke engine.
Brief information: The crankshaft is designed to convert reciprocating energy into rotational energy. In other words, the crankshaft. This unit is not very complicated in design, but requires very precise weight distribution and proper installation. Also, certain conditions are required for normal operation.
Factory puller
The rotor can be removed using either a factory puller or a homemade one. The option with a factory and homemade puller has its pros and cons. I'll start with the disadvantages of the factory puller.
The main disadvantage of a factory puller is its price. A factory puller is very, very expensive. About 500-600 rubles. But price is essentially not a very important criterion for me. Versatility, reliability, ease of use and durability are much more important to me. Unfortunately, the factory puller does not have all these advantages, except perhaps ease of use.
The versatility of the factory puller is zero and, unfortunately, it is only suitable for a certain series of engines. And if you need to repair a scooter that is not widely used in our country, then you will also have to buy a new puller for it. And this will be very, very difficult to do, since tools for rare models of scooters are as rare on sale as spare parts.
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Alpha Moped (72): Specifications
The alpha moped (72) is the most common means of transportation for light motorcycle enthusiasts. This is due to the price of this equipment, its functionality and repair. The travel, speed and small amount of fuel needed to drive this vehicle were supplied by an Alpha moped (72 cubic meters). Popular alongside the most famous Japanese brands. This is no coincidence, because the engine that powers these lightweight motorcycles is an exact copy of Honda's Japanese Cuba, which is significantly comparable to the AK-47. Single engine 139 FMB 72 cc. cm works in any weather conditions and does not require frequent repairs or replacement of spare parts. Technical characteristics allow this vehicle to be used in the most extreme conditions, including in the cold, on sand and on any SUV. This is the best light motorcycle for Russia. In rural areas you can often find Alpha 72 mopeds. Photos of this model are easy to recognize. Simple and concise design, low cost, good speed, maneuverability, maintainability, efficiency and a number of other advantages. this is what stands behind the reputation of this mode of transport.
Unique ability to intersect
Record for passing light motorcycles. This is an Alpha moped (72 cu m). The characteristics of its engine, its size and weight are very significant advantages. The ability to overcome any obstacle in the Alpha thanks to its light weight. 81 kg. This lighting technology does not require a powerful and heavy motor for confident movement in sand and mud. Whether you need to overcome a stretch of deep and sticky mud, a steep climb through sand, or cross a small river or river, you can always get off the moped and help it cope with a difficult section of road by pushing it forward like a bicycle.
Because the Alpha wheels are thin, they can be submerged in wet sand under the rider's weight. But without the latter, this moped can be pulled on any road, helping it run the engine in first gear at low speeds. In urban conditions, if necessary, at the intersection of stairs or high curbs, the Alpha can climb like a regular bicycle. That's why the most remote corners are accessible to this lightweight motorcycle in the riverside forest where you can only ride a bike. Many lovers of hunting, fishing and mushroom picking prefer this moped because of its light weight. It is impossible for heavier and more powerful cars to drive along the path taken by a fallen tree in the forest, but for the Alfa there is no problem.
Good speed
The ceiling speed for this moped is 70 km/h, which is quite enough for highway driving. The Alpha's weight is light, and control is noticeably lost at higher speeds. Some fans of this technique are trying to modify the Alpha (72) moped, insert a more powerful piston, a zero-resistance filter, increase the gear ratio, change the ignition system, install it before the curve and achieve an increase in speed to 90 km / h. But for city driving in traffic jams, on country roads, on earth and gravel, the Alpha speed is sufficient without all these modifications, and with the increase in power and speed of mopeds, many parts begin to take their toll, and components wear out faster.
