Originally posted by mglavin
How about a HANSON modified Zenoah with a tuned exhaust. I have three of these over the years. Still own one. There is not a glow engine I've seen flown that can hold a candle to the lifting power of this beast..... Were looking at 4hp with this combination... I am quite sure more power could be had with additional mods. 
You're using a Hanson tune pipe? How long is it is it heavy?