Fastening tool with an internal combustion engine with a unique opening and closing chamber abutment

A device, comprising:

• a fastening tool including an internal combustion engine configured to drive a fastening member into a supporting material, including:
• a cylinder;
• a propelling piston slidably mounted in the cylinder;
• a cylinder head;
• a chamber wall;
• and
• a pin guide having a bore therethrough through which the fastening member travels during fastening to be ejected from the fastening tool, wherein
• the device is configured such that the chamber wall is movable relative to the cylinder head so as to close an opening of a combustion chamber formed at least by the interior of the cylinder, the cylinder wall and the cylinder head,
• the device is configured such that that movement of the pin guide moves the chamber wall due to mechanical linkage between the pin guide and the chamber wall, thereby closing the top opening of the combustion chamber, and
• the device includes abutments in fixed relationship with the chamber wall that slide along an outside of the cylinder with movement of the chamber wall relative to the cylinder.