First thing, you don't know enought about glow engines to get the Saito needlevalves adjusted properly. Now you can keep playing with it till you ruin the engine and a few airplanes or find someone with enough experience to set the engine for you, simpliest way. I have seen the broken motor mount screws several times before and it is always improperly adjusted needlevalves. It seems strange but that is probally what it is. Once this engine is adjusted properly it is very smooth and powerful.