Okay, the Nexstar's white monocoat can be very helpfull. After you run the engine at full throttle and get a good stream of goo running under the wing and/or under the fuse; What color is is the goo? If it's still just as green as it was when it left the bottle you are to rich. When mine is running it's best the "goo" is barely green and has noticable carbon in it (black stuff). If your instructor is trying to tune for smoke trail he may have gotten so rich that the engine is not getting hot enough to produce smoke. The other posibility here is your glow plug may not be staying hot enough. Go to you LHS and step up the heat... good idea now with winter comming fast anyway.