okay, first of all, what kind of plug do you have in it? i would reccomend an os #8 for your evolution and most other 2 strokes. it really seems to be the plug, but it could also be that your low end is amazingly rich. it is hard to say. you said you put a new plug in less than two flights ago. if you can get a picture of the bottom of your glow plug as it is now, (coil facing the camera) i may be able to tell you your problem. resolution in the picture is first priority. size comes later. also, along with the picture, could you tell me what fuel you are using? i need to know the nitro content and the oil content along with the make.