would have to disagree with you on the Sig 73", i ripped the firewall clean out of mine in the air with a moki 1.8 trying do a waterfall. the engine actually landed in a water hole and cracked....the joke at the field was "i did a waterfall, it fell in the water" when i called sig ( trying to get something free!) they told me the plane was only rated for 1.2 - 1.5 glow and 2.4 gas FPE only.....whatever!