Yes, I would put the piston(s) at about the middle of the stroke. While one piston is on its upward stroke, rotate the flywheel backwards ever so slightly…Now insert the wooden dowel inside the plug hole and try to push the piston downwards, you will feel the piston move and hear a little clunk if slop is an issue. Oftentimes you will hear the clunk just by rocking the flywheel back and forth slightly with both pistons in the middle of their stroke. Please don’t turn the flywheel backwards excessively though, you might jam/snap the rubber veins off the water pump impeller. Keep in mind these engines have a fairly loose piston to cylinder fit, so don’t mistake normal sideways piston slop with actual rod slop.
