I hope you can find the information you are looking for. The plug gap should be pretty common as it should be the same for all Zenoah 23's. Sadly I don't have that information right now.

I looked in two places for the drawings for this heli and could not find it. Maybe an e-mail to the manufacturer could lead better results. [link]http://www.miniatureaircraftusa.com/default.asp[/link]

Rafael