Originally Posted by
Roelof
You have to mount only the combustion chamber. Get a piece of 1mm thick solder, bend the end tip in an L-shape and put it through the plug hole.
Turn the crankshaft arround and sqeeze the solder with it between piston and chamber. Take out the solder and messure the sqeezed part, it must be about 0.5mm
Does the 0.5mm differ for high altitude? We are running at 1800 m above sea level.