I have been running a Saito 150 ( with a 16x 6 ) inverted in a 1/4 scale Balsa USA Cub for the last 2 or 3 years. It flies like a dream. You can putt around as slow as you like, remember you can always throttle back. Just had my first flight on a 1/3 Druine Turbulent with a Saito 150 also inverted (classic 16 x 6) and am currently assembling a 72"Katana ARF with a Saito 150 Dual Plug with pressure pump) which is also inverted. I also run full time on board ignition on all my glo engines.