My bike is a '97 YZ 125. This is my first bike and I'm slowly learning everything about it. I am having a problem where my bike will run great, then the next time I go to start it up (1-2 days later), it either won't start, or it starts and won't stay at idle then eventually foul the plug. I am running a BR7ES plug and 32:1 using Yamalube. I am doing only trail and pit riding, so I am not really going "balls to the wall" all the time. I don't know how to jet (yet) and I'm debating whether I should attempt it myself or just bring it in... Help!