Dirtrider. Irish, where did you come up with the .63 mm number?
Kinda hit it sideways with that one. With a spacer, the compression ratio will drop, but you do still get to keep the increased displacement. without the spacer the piston is likely to hit the bottom of the head. As for working with your engine, I can't say. All these chinese manufacturers have their own designs I think. Based on the same honda design.