The Minsk motorcycle is a legendary product of the Soviet and post-Soviet era, one of the most popular two-wheeled vehicles in the latitudes of the CIS. It is a lightweight vehicle with an engine capacity of 125 cc. cm was very popular and was released in a fairly large volume. The secondary market is literally filled with offers for the sale of this motorcycle. It is simple in design and maintenance, unpretentious, cheap enough, perfect for a beginner. All these qualities also attracted individualist masters, thanks to whom tuning on the Minsk motorcycle became very popular, due to its comparative simplicity and a decent result. Thanks to technical tuning in Soviet times, these models participated in sports competitions, crosses.
Why tuning is needed
The meaning of any tuning is primarily to configure the vehicle in accordance with their needs. This applies both to the technical side and the appearance. The internal (technical) tuning of the motorcycle involves forcing the engine, changing the suspension, brakes. Refinement of the appearance involves painting, polishing, chrome plating, installation of additional, including aerodynamic, dodgers. Tuning the Minsk motorcycle, both external and internal, is not only possible, but even necessary. The fact is that when releasing this vehicle, engineers were primarily guided by accessibility and simplicity. Nevertheless, no matter how simple it may look, the potential of Minsk is present, which means there is room for improvement.
Intake loss reduction
The engine is the main component of any vehicle. For motorcycles, it is the power unit that provides the basis for the design and shape of the frame, the characteristics of the suspension. Forcing the engine is the main operation of tuning a motorcycle both in a complex and for individual nodes. The task of forcing is to increase engine power.
One way is to reduce intake losses. The first air supply obstruction is the air filter. As a rule, the original Minsk air filter is paper, less often kapron or metal. It will be superfluous to clarify that the throughput of such filters leaves much to be desired.
Spread are foam rubber air filters used on foreign motorcycles. Such filter elements provide minimal air resistance at the inlet, while having good cleaning characteristics. To reduce vibration and air noise at the inlet between the carburetor and the filter, a receiver is installed - a container (usually made of plastic) with a volume of about 10 times the cylinder.
Improving the quality of the air-fuel mixture
The formation of the air-fuel mixture in this vehicle occurs in the carburetor. To reduce losses at this stage, the nozzles and the surface of the diffuser are polished. Such a tuning of the Minsk motorcycle with your own hands can be done with the help of a thick stiff thread and Goi paste. The amount of fuel mixture entering the cylinder depends on the diameter of the diffuser.
A significant increase in maximum speed can be achieved only by replacing the carburetor. In the 90s, carburetors of the Japanese company Mikuni, manufactured at that time in India, were installed in Minsk. With proper adjustment, the motorcycle accelerated more dynamically, had great traction at low revs.
When adjusting the carburetor, the parameters specified in the instructions should serve only as a starting point, but not in any way reference values. Any carburetor is individually adjustable. An important detail is the contact density of the contacting planes: carburetor and adapter. The tightness of the connection significantly affects the life of the engine.
Increase in working volume
One of the most common ways to increase engine power is to increase the working volume. Tuning the engine of the Minsk motorcycle provides for a cylinder liner bore, but no more than a second repair size. Exceeding this standard will inevitably lead to problems with strength, selection of the size of rings and pistons. As a result, the result will not justify the costs. Alternatively, you can completely replace the cylinder with another, larger working volume, but in this case difficulties with the coincidence of the purge channels are inevitable, therefore this technique should also not be considered optimal.
Refinement of the standard cylinder
The best solution is tuning the Minsk 125 motorcycle with the refinement of its standard cylinder. First of all, it is necessary to eliminate the possible displacement of the purge and bypass windows. The purge of the fuel mixture in a two-stroke engine depends on their correct position, which directly affects the acceleration dynamics, efficiency and top speed. To do this, excess metal is removed from the liner previously removed from the cylinder with a mechanical or manual tool. All work involves raising the window by 2 mm, boring the radius of curvature and rounding sharp edges. Such an internal tuning of the Minsk motorcycle is able to increase the number of maximum revolutions by 1000.
Exhaust system tuning
A significant impact on the power of two-stroke engines is provided by the exhaust system. Tuning the motorcycle "Minsk" does not provide for the refinement of the exhaust system due to inappropriate. The best solution would be to replace it completely; as an alternative, you can make a silencer of your own accord as a resonator. In addition, the exhaust system must be adjusted, which, when correctly performed, can add from 10 to 15% of the power.