Determine the condition of the engine. The ideal option would be new and run-in. If the source engine is old, buy a new crankshaft, piston rings, bearings, cuffs, and tune in to painstaking work. First, completely disassemble the power unit components.
Get matching Windows in the sleeve with the channels in the jacket of the cylinder by the method of metal removal. Make sure that the thickness of the shirt and the neck of the crankcase remained at least 3 mm. To handle, use a drill with a set of cutters and scrapers. Achieve symmetry and high purity surface of the purge channel. If, after processing the surface of the channels will be smooth to the eye and to the touch, buff it is not necessary. Be sure to leave unchanged the height of the top of the overflow window and the vertical angle of the purge. The front edge of the overflow window make sharp, and the upper and lower edge of the upper inlet ports will opalite radius equal to the thickness of the sleeve.
Check that the skirt of the cylinder freely entered into assembled without gaskets Carter. If necessary, remove the excess metal in the throat of Carter. Passageways between the shirt and Carter adjust to pattern the contoured passageways shirt. The skirt of the sleeve should not block passageways. If overlap is present, remove the jumper and adjust the window in the sleeve, respectively, the window in the crankcase. Hone the intake window so as to form a smooth and stepless transition from the round cone to rectangular, with rounded to exhaust the window.
Outlet channel is a good line and be sure to Polish it. Podpilivaya the top and bottom edge of the window, give it an oval shape. Remove the chamfer on the outlet and top overflow Windows. Also remove the chamfer from the piston rings and the top ring matte chrome. The clearance ring lock sawed up to 0.2-0.3 mm. Surface of the cylinder bore treated with a grinding, honing or lapping. The clearance between the piston skirt and the cylinder wall bring to 0,04-0,05 mm.
Treat the Windows in the piston skirts so that they fit the Windows in the skirt of the sleeve. Edge on the skirt of the piston is round with a radius of 0.5 mm. Itself the piston skirts Polish. At bottom dead center, the piston must not cover the bottom edge of the top of the overflow window. To do this, either clear the flats, or protocide the piston head along the radius of 70 mm to the desired value. The bottom of the piston leave not thinner than 5 mm. the ends of the lugs of the rod mill so that their sizes did not differ more than 0.1 mm. Piston pin lighten groove beneath the cone, protecting the work surface from damage.
Check radial clearances in the upper and lower connecting rod bearing. They should be no more than 8 µm (top) and 12 um (bottom). When gaps more data values, replace the crankshaft for a new one. Ypressure fingers crankshaft separately from each cheek. Regular balance holes plug with aluminum, and its weight counterbalance with lead plugs inserted in the lower part of the cheeks of the crankshaft. Themselves cheeks will protocide to 100 mm in diameter, avoiding damage to the axles. The diameter of the axles themselves reduce to 17 mm using fine sandpaper.
Achieve a smooth pairing of the surfaces of the connecting rod, avoiding the scratches on the mates. The outer surface of the connecting rod necessarily Polish. Before assembling the crankshaft RUB with molybdenum disulphide all of the lower connecting rod bearing. The crank pin press without distortions. When this axial clearance between the lower connecting rod cap and cheek should be 1,6-1,7 mm. Carefully align and balance the crankshaft.
The surface of the crank chamber of the crankcase hone clean. Aluminum rings secure with epoxy glue and 3 screws M5 flat head screws. All the clearances in the crank chamber fill with epoxy resin filled with aluminum powder or with a plasticizer. After the treatment collect Carter Hermetica without a gasket. When installing the crankshaft lock it from longitudinal displacement in two washers. All screw connections of the motor assemble with anaerobic sealant.
Forced engine requires gasoline with an octane rating of at least 93 and high quality oil for two-stroke engines.
Advice 2: How to boost a motorcycle engine
To boost motorcycle engines developed and applied in practice a variety of methods. Some of them can be applied in a home garage, the application of some is possible only in specialized enterprises for motor tuning. Some methods are characterized by their relative simplicity and low cost, others are very sophisticated and can cost much more expensive motorcycle.
Before you boost any engine, remove the set power limiter. Without this process forces loses all meaning. Often, instead of the power limiter includes a maximum speed limiter. Delete it, too. After forcing the engine, most likely, the motor will develop maximum power and torque at higher revs.
Chip tuning is a reprogramming of the engine management system in order to develop higher. In practice it seems simpler to force changing control unit injection. In order to do it yourself, you do not need extensive knowledge. Purchase this unit for motorcycle in the bike store, selling tuning kits. Installation instructions will be included with the product. This method of storage is suitable only for modern motorcycles of foreign manufacture.
If the motorcycle has carburetor the power supply system to boost a wide variety of methods. Standard carburetor hone, increase the diameters of the Windows, nozzles, change the settings. Or install a dual carb, twin cylinder engine. If you have the opportunity to purchase specially designed sports carburetor, buy and install it. But not all models of domestic motorcycles you can choose the right model.
A forced exhaust system of the engine is also worth it to upgrade. Install flow muffler, purchased the same bike store. More serious tuning is to install a completely new sports exhaust system. For her installation in the engine, you may have to contact the tuning firm.
Turbocharging is a serious way to boost the engine. Not all motorcycle engine tuning companies produce ready-made options. Even in the presence of kit-the kit turbocharger refer to the experts to install it on the bike.
Tuning of the cylinder-piston group of the engine is forced to increase the compression ratio of the engine. To do this, change the combustion chamber by milling the pistons, change the stroke of the pistons by installing a sports camshaft. Adjust the timing and angles of the ignition setup for the new compression ratio. Note that in many cases, to install a turbo or compressor on the engine need not increase, and the decrease of the degree of compression.
In addition to these, purchase and install aftermarket kits, without which none boosted engine. This air filter zero resistance, racing camshaft, capable of operating at high and ultra-high speed sports ignition system, and more. All depends on the extent of the forces and financial possibilities of the owner.
Forced engine consumes more high-quality fuel with a higher octane number and a special oil for uprated engines.
And engine tuning is more sensitive to the timeliness and quality of maintenance.
And engine tuning is more sensitive to the timeliness and quality of maintenance.
Advice 3: How to speed up the engine "Minsk"
The motor sportsmen want to become many, but not all beginners have enough funds to buy ready-made sport bike. Exit in such situation – to prepare the standard machine. Engine "Minsk" is one of the most simple in design and easy to small forces. Note that while the engine is reduced in proportion to power.
You will need
- - the engine "Minsk" M-105, M-106 or M-125;
- - mechanical workshop;
- - rings and seals crank chamber;
- - carburetor K-36И;
- - magnetos M-24G;
- - spark plug PAL-14-8 or BOSH-260-280
If you choose the base engine, prefer M-125. Compared with previous models M-105 and M-106, it has better cooling, which increases its force for sporting purposes. If for model M-105 and M-106 the power of 9 HP is almost the limit, for the model M-125 can be achieved 10,3-10,8 HP in the average machine shop. The engine should be well run and have serviceable parts and mechanisms.
Completely disassemble the engine. In both halves of the crankcase, insert and secure the rings which will reduce the diameter of the crank camera to 121 mm. Change the oil seals of the crank camera on a specially designed sports model. They must withstand a pressure of at least 0.8 kg/sq cm Change timing: phase of the release must be equal to 164 degrees, the phase of the purge – 108 degrees, the phase of issue – 128 degrees.
Instead of the standard, set the carb-TO-36И with a cone diameter 27 mm. Its main fuel jet needs to have a capacity of not less than 0.25 l/min inlet ports in the piston sawed to 25 mm so that they coincide with the vent Windows on the cylinder of the motor.
The intake manifold will extend to 300 mm. the length of the intake tube from the bore to the carb must be 100 mm, the inner diameter of the intake manifold needs to be 40 mm, the length of the manifold from the carb to the air filter – 150 mm. the ignition system set magneto M-24G. The ignition timing set at the level of 2.2-2.5 mm before TDC. Screw candle type PAL-14-8 or BOSH-260-280.
Bronze separator-connecting rod crankshaft replace the duralumin type D-16T or-95. Also suitable homemade cieniowane steel or steel of grade 45 without heat treatment with the obligatory silver of the surface.
Conduct additional polishing of the channels of the barrel, check and adjust, if necessary, the cross section of these channels, as well as the angles of the exit purge. Factory level processing of these surfaces is not sufficient for sporting purposes.
Air filter replace larger, with a tank capacity of not less than 3 years and paper filter elements. After running forced so motor install the carb with a 28mm diffuser, the length of the tube from the bore to the center of the spray increase up to 135 mm, the length of the manifold from the carb to the air filter, increase up to 170 mm.
Forced in this way the engine use gasoline grades B-95, B-100 or A-98. Motor oil MS-20 in a ratio of 1:20. To further enhance the power you will need to install the sports of the crankshaft, piston and piston rings, the transition to a higher timing, and application racing muffler and carb.