just to ad my two cents
there are a number of .60 -1.20 size gas engines available on the market now at extremely resonable prices
not only are they more afordable to opperate they can swing bigger scale props
http://www.troybuiltmodels.com/items/RCSSV17-H.html
this 17cc has got great reviews with comprobale weight
http://www.troybuiltmodels.com/items/AEROVATE20R.html
this is the one i will opt for
watch the video
Tighe OMeara