I built a diamond dust delta wing with an os max V (40) ducted fan engine. What is the best fuel to use for max rpm and easy tuning? All I had was 30% heli fuel and it was nearly impossible to tune and kept burning out glo plugs. I ran it on 15% sport, it ran good but not the screamer I was hoping for. The local hobby shop has some 20/20 should I try this? Any help would be much appreciated.