You will need
- - a set of files and needle files;
- - welding Assembly;
- - piston rings;
- - К65И carburetor with intake manifold from Izha Planet
Make sure that the engine is in good condition crankshaft bearings and seals. Crankshaft is in perfect condition. Purchased the piston is prefabrication, the intact ring of the correct form tight and retaining rings.
Measure by-pass and blow-by channels in the cylinder. If their size there is a difference, cut out the gasket under the cylinder on the contours of the crankcase and attach it to the cylinder. Then remove the bevel in the channels to a depth of 10 mm to match made a stencil. The angles of chamfer zakruglenie a radius of 3 mm.
Sawed the inlet window so that it rose to 1 mm. When the operation is running continuously make sure that the engine piston in its bottom dead center did not open its upper edge is a window.
Follow the grooves in the bottom of the piston to improve gas distribution and heat sink of the motor. Grooves make flat (not round like the bottom of the piston) and place them symmetrically. They should reach almost to the center of the piston. Transitions align with sandpaper.
Piston rings, Polish with sandpaper on the inside, and remove the chamfer from the inner radius of 0.25 times the width and 0.5 in height. Piston skirt shorten by 5 mm, if you're not going to change the carb. If the carb plan to change, shorten the skirt 11 mm. In this case cut away at an angle, and the bypass window in the piston will move under the window in the sleeve.
The piston will strike the bottom of the groove under the ring. Close with a stopper and symmetrically on the other side drill a recess with a diameter of 2 mm to a depth of 2 mm and back press aluminum wire. The place of pressing, align the needle files. The bottom of the piston, Polish to obtain a mirror surface. Remove more small chamfer around the entire circumference of the piston skirt.
Install the carburetor К65И with nozzles 32 mm and the intake manifold from the motorcycle IZH Planeta. The manifold side of the cylinder cut by 30% and grind the manifold to the size of 24х34 mm When fitted on the carb should take a horizontal or slightly inclined position. For mounting manifold to cylinder studs bend to the required angle. Then adjust the shirt of the cylinder in the intake window to seamless match the manifold.
When assembling the engine, discard the head gasket of the engine block. Flange seal with adhesive, sealant and tighten the carburetor without using excessive tightening forces. Install the muffler of the sample in 1980. It has a long cigar-shaped form with smooth narrowing at the end. Installation possible move it toward the cylinder, shortening the length of the outlet manifold to a value of 300-350 mm. He inside of the muffler horses remove. Put the oil filter from KAMAZ as air.
Advice 2 : 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.
Advice 3 : How to increase power in Minsk
MMVZ for engines installed on motorcycles "Minsk", there are several ways to increase the power. Each of them has its own characteristics and is used both individually and in combination with other methods of force.
You will need
- - tuning kits;
- - new spare parts;
- - repair equipment
Hone the cylinders to the repair sizes of pistons. Install the new piston group. This way, you will increase cylinder displacement, which in turn will increase power without increasing engine speed. This method forces only makes sense for new engines.
Install flap valves boyesen and increase the height of the overflow window relative to the exhaust window. Effect – increase power at low revs, allowing the motorcycle easier to move, quickly accelerate better move in difficult conditions and under load.
Hone the outlet port. It will be kept open a longer time and be able to pass through a greater amount of gases. The maximum engine speed will increase along with his power through better venting of the cylinder at high crankshaft revolutions. But at lower speeds power is reduced because part of the fuel mixture is to burn effectively.
Improve scavenging to the previous method of forcing was more effective. To do this, extend the bypass regular Windows and will protocide third vent channel. This will improve the filling of the cylinder at high rpm will not accumulate the working mixture in the crankcase.
Install the carburetor with a larger diameter. Wider diffuser will allow the carb to prepare for cylinder a greater quantity of the working mixture, which is extremely important for forced engine. If you do not perform this modification, a more powerful engine will not be able to develop their full potential, as it will constantly experience "starvation" - the lack of fuel mixture.
Install the resonator to the intake system. While tuning the resonator should have the opportunity after the installation to configure it to work on a certain speed, usually close to the maximum. This method will return a portion of the working mixture out of the cylinder into the outlet port by blowing back into the combustion chamber. And this, in turn, also will give some power gains.