Most quality cast pistons have a silicon content of 18% or so versus a forged pistons max of aprox 12%. This higher silicon content results in less piston expansion and better high heat thermal properties which is desirable and critical in a 2 Stroke engine. The forged piston is stronger due to its grain structure which is desirable for a 4 stroke application.
I have been involved in mechanics and motorcycling from a young age. I formed Cycle Improvements in 1981 and still have the same passion to learn today as when I started. Hope you find this blog interesting and educational.