Cashpo: Thanks for the reply. When I get the courage to do the rebuild, I will certainly try the 7" CG location. What are you using for a prop on your OS 55? I used a Master Airscrew 11x5, and it had plenty of pep. Spiro told me that the Flyingthingz lawnmower needed a lower pitch prop - he uses an APC 12x4, and that this lawnmower didn't like speed, but needed thrust at a lower speed, which the lower pitch will give you. The main reason I used the MA was because it was black and looked nicer with the red lawnmower (and I had one) For your next flight, try a lower pitch, it might surprise you. Spiro also told me to have it sit nose high, about 5 degrees to help it get off the ground, and he said to have some up elevon trimmed in as neutral. Spiro also uses 30% nitro - mine did well on 15%. My rebuild will probably wait until the winter building season. --Milt