My bike is running very lean. I have had it to 2 shops, paid lots of money and it is still not running. I supposedly had it re-jetted twice. The bike sat for a long time before I bought it. I am planning on taking the gas tank off and cleaning it out and draining the lines. I donĀ“t think they jetted it correctly. Here is the big question, there is a line that runs to the carb on the right side of the bike that on the end there is a cap with a slot in the head of it, what is this line for ? Is it a mixture adjustment or what. Thanks for your help, Gary