I misplaced my camera at the moment, but I haven't dug into either engine other than to verify that there isn't a bridge in the exhaust port via taking the plug out and looking in the hole at the right angle... and by the "new versus old" I was talking about the schrouding/plastic housing, on the newer models the shrouding is very round and smooth, the older style is square and clunky, the older ones having a square muffler, the newer ones with  a rounded rectangle muffler, with the hole about 1/2" above the exhaust port, which I haven't verified that this 30cc has, just assuming...</p>

yeah, right now "old trusty" is a beat to heck tower trainer with an old bushing OS .40, starts on the first flip (got the whole plane for $75), but there's just so much you can do with a high dihedral wing plane... other than inverted figure eights (takes practice), I have a hard time making a full flight before being bored out of my mind...</p>