I Have Both Showtime 90 and Showtime 50. My 90 has OS 120 AX in it and I balanced it 1/4" forward of CG Recommended in the Instructions. It Flies Super and Very Stable. I didn't install Wheel Pants so I can land on Grass or asphalt. Almost needed zero Trimming. I love to fly Only with SFG's installed. Rock Solid performer with CG where I set it at 7 1/4" back from root of front leading edge. I set 2 Dots on Top & Bottom of wing in bright Orange and Green Repair Mono Film with strong adhesive on it that is made for accenting or Field repairs. Make them with Standard Office Single Hole Punch. Orange Dot I place dead on recommended CG and green Dot 1/2" in front. I Balanced Showtime half way between 2 dots on GP Balancer. Another Change I Did is mount My Engine Upright with the longest OS Extension on the Muffler. I'm Just breaking in OS 55 AX on My Showtime 50 built the Exact Same configuration. I bought it because I loved How Showtime 90 Flies and handles. And Economical to Fly smaller Version. Be Test flying it in next week or so. My E-mail [email protected] and I have Photos I can send if it would help. Showtime 90 My Best Flying Bird of My 10 Bird Hangar. I have New Goldberg Yak 54 Still to test Fly 67" Wingspan with OS 120 AX in it. I like use APC 16 X 4WIDE Props and works Super on 120 Engine with backing of throttle diving or back side of loops so don't over Rev Engine. Good Luck Working Bugs out Your Showtime IT'S GREAT PERFORMER!!! Well worth Time 7 Effort!!!