You can't directly convert a four-stroke engine to a two-stroke engine. The fundamental designs are too different. A four-stroke engine relies on valves and a complex crankshaft/connecting rod system to complete its four strokes (intake, compression, power, exhaust), while a two-stroke engine uses ports in the cylinder wall and a different crankcase design for its two strokes (intake/compression and power/exhaust). The cylinder head, crankcase, pistons, and even the carburetor/fuel injection system are completely different.
To create a two-stroke engine, you would need to essentially build a completely new engine from scratch, using parts designed specifically for two-stroke operation. There's no straightforward conversion process.
