Hi there, I bought my Cermark Spitfire about a year ago but had been flying my 60 size Spitfire from World Models with a YS-110. That was my rocket. After 165 flights, it went down last week and was destroyed completely. Now I am all about building that Cermark Spitfire. I am hanging a YS-140 Sport on the fire wall with a Hyde Soft Mount. I have another WWII warbird...the Hawker Hurricane which is about the same size...71.5 inch wingspan and weighing about the same and it is powered with a YS-140 Sport and boy, does it haul the mail! I have had a lot of success with the YS-140 model on this size plane. The props I start with on maiden and for about the first 20 flights are the APC 16x8...after that I go down to a 15x10...and then eventually end up about at 14x12. The YS has plenty of torque and power to turn these higher pitch props and increases the speed. I just ordered the rest of the set up including high-torque servos, gas tank, and all the other bits and pieces I'll need. The first thing I am going to do is to spray all the exterior parts with Top-Flight "flat clear"! This protects the paint job from chipping during construction as well as it is fuel-proof. I'll be posting some pics as soon as serious building begins.