Why would you want to put a 15cc gasser in this airplane? I have this kit in my inventory along with a Saito .62. The recommended engine size is a .29 to a .40 2-stroke glow. or a .35 to .45 4-stroke. This bird is designed to fly on the wing, not on the prop. I've looked at the replies to this thread and am amazed at what some of you are doing to this wonderful airplane. For comparison, a friend of mine had a Senior Telemaster (nine foot wingspan) with a Saito .91 for power. He asked me to test fly it for him as he was too nervous to fly it himself. The airplane flew great (of course!), The engine preformed flawlessly (again, of course!), but there was a problem. I could not slow the thing down enough to land! We tried lower pitched props. We tried adjusting the idle as low as we dared. The only way to get the thing down was to kill the engine on final. Unacceptable. The solution was to swap out the .91 for the Saito .82. That did the trick. A perfect match of airframe and power plant! Loops from level flight were effortless. Verticals were tall enough for nice stall turns and wingovers. And landings were a thing of beauty. Remember, this was a 9-foot Telemaster! It could maintain altitude with the throttle cracked open just above idle. Touch-and-go's were especially fun. Low and slow fly-by's down the centerline took forever. One guy even complained (with good humor) I was tying up the runway for too long. I guess what I'm trying to say is, you could do better than to simply stuff as much power as possible in an airplane, especially something like the Kadet Senior.