Moped "Alpha" (72 cu.): Technical specifications

Moped "Alpha" (72 cubic.) Is the most common means of transportation among fans of light motorcycles. This is due to the price of this technique, its functionality and maintainability. Passage, speed and a small amount of fuel, which is necessary for driving on this transport, put a moped "Alpha" (72 cubic.) In popularity in a row with the most famous Japanese brands. This is not accidental, because the engine that stands on these light motorcycles is an exact copy of the Japanese "Cuba" from the firm Honda, which is comparable in reliability with the AK-47. Single-cylinder engine 139 FMB volume of 72 cubic meters. Cm works in all weather conditions and does not need frequent repair and replacement of spare parts. Technical data makes it possible to use this transport in the most extreme conditions, including driving in the cold, on sand and on any off-road. This is the best light motorcycle for Russia. In the countryside, you can often meet the moped "Alpha" 72 cu. The photo of this model is easily recognizable. Simple and concise design, low price, good speed, patency, maintainability, profitability and a number of other advantages - this is the basis of the reputation of this type of transport.

Unique cross-country ability

The record holder for passing through light motorcycles is a moped "Alpha" (72 cu.). The characteristics of its engine, dimensions and weight are very significant advantages. The ability to overcome any impassability in the "Alpha" is due to the light weight - 81 kg. To ensure a confident movement in the sand and dirt, for such a light technique does not need a powerful and heavy motor. If there is a need to overcome a section of deep and viscous mud, a steep climb along the sand, or to cross a shallow stream or a river, you can always get off the moped and help him cope with the difficult part of the road, pushing it forward like a bicycle.

Due to the fact that the wheels of the "Alpha" are thin, they can get bogged down in the wet sand under the weight of the rider. But without the latter, this moped can be dragged along any off-road, helping it to work the engine in the first gear at low revs. In urban conditions, if necessary, cross stairs or high curbs, "Alpha" can be raised just like a normal bicycle. That's why for this light motorcycle the most remote corners are available in the forest, on the bank of the river, where you can only go by bike. Many fans of hunting, fishing and collecting mushrooms prefer this moped because of their low weight. For heavier and more powerful vehicles, it's impossible to drive along the path that the fallen tree in the forest has blocked, and for Alfa there are no problems.

Good speed

The speed ceiling for this moped is 70 km / h, which is quite enough for highway traffic. The weight of the "Alpha" is small, and handling at higher speeds is noticeably lost. Some fans of this technique try to modify the moped "Alpha" (72 cubic meters), put a more powerful piston, zero resistance filter, stars with an increased gear ratio, modify the ignition system, setting it ahead of the curve, and achieve an increase in speed to 90 km / h. But for movement around the city in traffic jams, along country roads, along the ground and gravel of high-speed capabilities, Alfa is quite enough without all these modifications, besides, with increasing power and speed, many important parts and assemblies of the moped begin to wear out more quickly.

The design of "Alpha" allows you to install on it more "solid" engine options, bringing its power to 8 liters. from. But the "Alpha" with these engines often require repair, the life of the most important elements of the running gear are much shorter, and they start dangerous vibration destruction. A more powerful motor would require an increase in the mass of the other structural elements. This would be a loss of many advantages, especially in the patency and economy, which moped "Alpha" (72 cu.). The speed characteristics of these mopeds are perfectly balanced with the lightness and strength of their construction and running gear.

Engine

The reliability and unpretentiousness of the 72-cubic four-cycle Alfa engine is due to its ideal design, developed by Japanese specialists. Even in a slightly simplified version, with the use of cheaper materials and smaller requirements for the quality of units, the engine 139 FMB works surprisingly reliably, which indicates the balance of all its structural elements. The power of this motor is only 5 liters. S., And the maximum number of revolutions per minute - 7500. However, thanks to a well-thought-out transmission with four gears, the engine of the Alpha perfectly copes with the normal loads in all ranges of its transmission capabilities.

Engine Construction

The motor design is very simple. In the cylinder head are two valves - inlet and outlet. Their work is provided by the timing star located in the same place, the rotation of which occurs synchronously with the magneto through the chain transmission. On the left side of the engine there is a foot-operated shift lever, which controls a very simple system of gears mounted on two parallel shafts in the motor casing. The oil pump is driven from the timing chain and located under the crankshaft. On the right side of the engine inside the crankcase is a clutch unit, which is controlled by a lever using a clutch cable coming from the left handlebar.

Prevention and repair of the Alfa engine at home

The motor of the moped "Alpha" (72 cubic meters.), Like any transport, requires regular maintenance and repair. Regular oil change is an important condition for prolonging its operation. The oil change process is very simple. The engine warms up, then turns off, and with the help of a drain hole located under the crankcase, the used hot oil is easily removed from the crankcase into a specially prepared container. Then a new oil is poured. Adjustment of the correct operation of the engine begins with the adjustment of the carburettor, by means of which it is possible to enrich or impoverish the mixture. It is also necessary to regularly check the operation of the valves, installing the necessary gaps with a special probe of 0.5 mm. Two or three times per season, it is necessary to check the tension of the timing chain, as well as the condition of the mechanism of its tension, rubber rollers and depressors. Any breakdown in the Alpha engine is easily removable. When losing traction, it is necessary to remove the cylinder head and check the integrity of the valves. Flaring the valves is one of the possible breakdowns of this motor. To restore their working capacity, they must be cleaned and re-rubbed with paste. This procedure is familiar to many owners of old models of Zhiguli. When the timing chain is broken, it is necessary to remove the generator rotor and replace all the elements of the gas distribution mechanism, and when assembling the engine, make sure that the rotor of the generator and the timing star are synchronized with the correct stroke of the cylinder.

The clutch must be disassembled once a season and washed in gasoline, as a viscous mixture of oil and metal powder accumulates inside it. With a regular inspection of the engine, proper adjustment and replacement of parts with signs of wear, 139 FMB will work reliably. Repair moped "Alpha" (72 cubic.) Does not require serious investment and can be successfully carried out with a minimum of skills and skills at home.

Recipes for increasing the power of 139 FMB at home

The most common way to increase the engine power of the moped "Alpha" is to replace the piston group in a variant with a large cylinder volume. Typically, this replacement adds power to the motor, but does not greatly affect the speed of the moped. There are other ways. The simplest is double ignition. You can make a step on the ledge located on the rotor body of the generator, cutting off the layer of 0.5 mm from the half of its metal surface, from the edge that first touches the sensor during the working stroke of the rotor. This will give an increase in power by 5-10%. You can increase the diameter of the intake and exhaust valves. To do this, it is necessary to drill holes in the cylinder head for wider valves taken from piston group 139 FMB with a larger cubic capacity. This operation gives an increase in power by 15-20%.

Maintenance and repair of the moped

Repair of the moped "Alpha" (72 cubic meters), caused by capital breakdowns, can be completely eliminated by conducting a regular preventive replacement of those parts that have obvious signs of wear. The chain on the moped should be replaced after each season or after 2000 km of run. The chain stretches very significantly, which increases the wear of both stars. Due to chain failure at high speed, a situation may occur with a sharp blocking of the rear wheel, which can lead to dangerous falls, injuries and even more damage to the motorcycle. On the road, this situation can cause the destruction of the elements of the tension of the rear wheel, severe deformation or complete destruction of tension nests. Artificial shortening of the chain contributes to the rapid wear of both stars. Tires after 7 000 km of run completely lose the relief of the tread and the force of adhesion to the road. They need to be changed after 2-3 operating seasons. The cables for controlling the clutch, fuel supply and the brake drum of the front wheel should be shortened after each operating season due to their extension. The rubber bands in the brake drums are gradually deformed, which increases the play of the wheels. They are also better to change after each operating season.

Vibration fracture

Some moped failures can be associated with the destruction of its load-bearing elements. The plastic front wing on the Alpha serves longer than the metal one, since it is less susceptible to negative vibrations. The engine mounts on the frame can also be destroyed due to vibration. To avoid this, you need to weld on them wide washers. The battery after 2-3 seasons loses up to 50% of its capacity, therefore its regular replacement is also desirable. Electrical clutch sensors and control of the turn signals should work in the normal mode. On them depends both safety during the movement, and the correct control of the switching speeds. The standard rear shock absorbers on the Alpha wear out, which can lead to undesirable friction of the rear wheel on the inner surface of the rear wing. There are luxury versions of the rear shock absorbers for the "Alpha", which allow you to put thick tires on the rear wheels, because with them you can slightly raise the rear of the motorcycle. With careful handling of fasteners, serious problems with the repair of this moped are unlikely.

Running in

Running a moped "Alpha" (72 cu.) Does not take much time and has several main conditions for getting the right result. It is necessary to strictly comply with the speed limit up to the first thousand kilometers of run, you can not overheat the engine, forcing it to work at maximum revs for more than 20 minutes, and also to change the oil after 500, 1000, 2000 and 5000 km.

Modifications

Overview of the moped "Alpha" 72 cu. Will not be complete without listing its major modifications. There are two versions of the frame for this moped. It is high, with a place under a large gasoline tank, and low, where the gasoline tank is small, and above it is the trunk. By their characteristics, both versions of the moped will be almost identical, except for the difference in the volume of gasoline tanks and a small run-out in the landing height. Alfa is made by a number of Chinese manufacturers, so there are many parallel names for the same model. For example, a moped "Omax Alpha" 72 cu. Is a purely Chinese version, and the moped "Orion" 72 cu. - the Russian assembly of the same model from Chinese spare parts, carried out at the enterprises "Velomotors".

Options for assembly

Existing modifications of "Alpha" (72 cubic.) May differ in some design elements. There are also luxury versions of this moped. For example, a moped "Alfa Racer" 72 cu. Has a more effective and dynamic form of seating and stands out against the backdrop of the other "Alf" spectacular sports contours of the gas tank. In fact, this is the same model of a moped. In luxury versions, hydraulic rear shock absorbers, alarms, plastic wings, more attractive decor elements, turn signals and lights are slightly more expensive, expensive coats and even folding bags of leatherette. But it will still be the same moped "Alpha" 72 cubic., With the same technical characteristics, but 30% more expensive.