A well-running engine also includes optimized compression. Because you should neither risk an overheating or even a hole in the piston, let alone renounce performance. It is important that the compression ratio is optimal for tuned engines. Air-cooled engines do not tolerate such a high compression as water-cooled. In addition, the crushing dimension must not be undershot, since otherwise the piston strikes against the cylinder head.

The compression is optimized by machining the cylinder head. The geometrical compression is determined by repeatedly multiplying the installed motor. At the same time, it is checked whether the crushing gap does not fall below a critical dimension of 0.8 mm for small motors and 1.2 mm for slightly larger ones.