i have a hp21 vt (yes there still get there),iam running the right fuel mix(nitro 15 with 22% oil as called for and the glow is for that eng. as per info on the eng. prop is a 7/4, ok this is what happens good start up (let it warm up befor giving any higher rpms) go up to about 6500 still not bad, back off and try to go to full power nothing it just dies,i have tryed diff props 7/5,7/6 8/5 8/6...................any help would be great