Stop in for a cup of coffee
hint:
Head combustion chamber volume: 70 cc
Gasket hole diam: 104.6 mm
Gasket thickness (measures) 1.06-0.96 mm depending on clamping force.
Cylinder diameter: 102.3 mm
Cylinder cc with piston 2 mm down in the hole: 23 cc.
Now you beat me to it! :D