Hi All, I flew my stinger 120 after changing the muffler to the b and b. I tacked it first and picked up 250 rpms on the 18x10 zinger and 120 rpms on the 20x8 zinger. I was suprised to find that the 18x10 pulled more vertical than the 20x8. On the fish scale the 20x8 looked the best But not in the air. I am thinking of cutting the 20x8 down to 19x8.Anyone have idears on that. Thanks wayne m.