hotwings is correct. You need to richen the engine to a point where you know its to rich then back it down a little. I use a very unscientific method to gage engine temp. Put your finger on the cylinder where the manufacture's logo is and if you can hold it there 2 seconds its to cold. If it burns your finger in less than 1 second its to hot. Now that my index finger is scared from repeated burns I'm using my other index finger.