Am in study phase for another month or so, making Decisions, etc. I've no gas experience for more airborne flight than string trimmer or lawnmower. Kit rec's gas 25 to 35 cc or fourstroke 120 to 150. I have older OS 120 FS (pre Surpass) and a ST 2500, Astro 120 twostrokes, (latter two ran fine on bench. Interested in engine input as well as "if-I-had-it-to-do-over" advice. I elected to go with BUSA after deciding Dynaflite wasn't what I wanted. Proctor someday maybe, after winning lottery. LOL, Let me hear fromya.