The power of the outdated two-stroke engine of the Izh Planet motorcycle, if desired, can be increased without even causing serious damage to the resource. This method was actively used by Soviet athletes in the 70s and 80s of the last century to prepare cars for motocross competitions and multi-day rallies.
It is necessary
- - mechanical workshop of average equipment level;
- - serviceable engine Izh Planet
First of all, polish the cheeks of the crankshaft and give the body of the brown-haired person a streamlined shape. This is a necessary attribute of the preparation of any two-stroke engine. Then carve new crank chamber cheeks with an outer diameter of 133 mm from steel grade ZOKHMA or ZOKHGSA. Reduce the balancing selection under the lower head of the connecting rod to 54.5 mm. Compensate for the imbalance by grinding a 28x20 mm hole from the bottom of the cheek at a distance of 38.5 mm from the center. Close the hole with a duralumin plug.
Lighten the crankshaft to make the engine spin easily to high rpm. To do this, mill his facial cheeks so that their diameter decreases from 52 to 40.5 mm. Close the resulting holes with duralumin lids, stamp and polish them. Balance the shaft modified in this way. All the changes made improve the agility of the motor at the expense of the smoothness of the ride.
To improve the smoothness and thrust of the engine, change the main bearings instead of the crankshaft. In this motor, they are the weakest part and quickly disintegrate. To eliminate this drawback, replace the inner rollers of grade 2505K with two ball bearings of grade 6205, ground to a thickness of 9 mm. Install them in the crankcase, heat to 100 degrees and insert them hot into the crankshaft. To supply lubricant to them, cut a groove 1 mm deep in the crankcase at a distance of 17 mm from the outer bearing retainer ring.
Seal the crankcase on the left and right sides with an oil seal from Java 638. Under the left 45 grade steel oil seal, carve a ring onto the crankshaft and polish it on the outside. On the right side, press a roller bearing 42205, ground to 10 mm, into the crankcase and install a cover with an oil seal from Izh-Jupiter. Plug the oil channels from the crank chamber, and instead install two plastic pipes with a diameter of 4-5 mm for the oil supply.
Replace carburetor. Soviet athletes put on "Mikuni" or K-62D from Izh Planeta-Sport. Or carburetors from ChZ-250, ChZ-500, famous for their reliability on rough terrain. Currently, a more modern tuning carburetor can be selected for two-stroke motorcycles.
To improve the operation of the ignition system, replace the generator with a modern model from the SOVA motorcycle. If you want to increase the power at high speeds, order the manufacture of a new electronic switch from the specialists. The result of all work will be a significantly more powerful motor with a doubled resource.