our ucan has been around for a while and we have mixed it in every posible way cg back, far back, forward and the rest and every time we come back to factory spec where she flies the best - interesting but true - we have a os91fx with stock tank, big fuel tubing and drilled clunk - 14x6wood or ms is perfect for us - we have tested all the props like the 15x4 etc - we like the wood because of spool up and the ms for stable t/r - we don't run the cowl because we are in israel and our temp's are to high - we run only morgan omega 5% and o8 os plug - the rest is all practise and mixing of radio - fly this baby slow and she bonks like a crazy horse not the super duper 3d plane but marvelous fun and t/r show off - we have also used other engines like the saito 100 but when your fx runs like ours it kicks ass - best