Hold on one second here. The point of the insulation is to keep the pipe hot at that point, which keeps the gasses hot, and moving at a faster rate due to thermal expansion. The gasses are pulled away from the head sooner and have less time for energy transfer. This prevents heat soak and can lower head temperatures by a few degrees or so; this is the reason it is good in a 4 stroke/turbo. So you guys are totally right on that. In a 2 stroke with an expansion chamber, gasses are being "pushed" back towards the exhaust port, somewhat sealing it. Note that these gasses may even enter back into the cylinder, or be against a closed piston depending on timing and pipe design. The time for energy transfer in this situation is increased, and will raise heat in the engine. I would not recommend using thermal wrap on a 2 stroke exhaust, especially with an expansion chamber. (A little background on myself-I am in school for engineering and have a 4.0, as well as 103% in thermodynamics; I hope I don't sound like a total tool with that, but I figured it's worth something.) Also i would recommend "rolling your own" CDI, there are many benefits including longevity and power.