Just curious, but given the size and projected weight of this plane (I can't ever remember building a GP model that came out LESS than the weight specified by GP), I was wondering if anyone else had doubts about this really being a 1.20 plane? Sounds like for real Chipmunk preformance, one will likely need at LEAST a big bore 4 stroke (YS 1.40, Saito 1.80, etc) or maybe even the larger 2 stroke glow (Moki, ST, etc) or as the others above have suggested, smaller, lighter gas engines.

Lee