Please don't put this in the mini forum I just never get answers there. Two minutes ago my brother had his bike warming up just setting the idle and stuff not really doing anything and he shuts it off. I check the plug because its been running rich, and its oily and black. But it ran two seconds ago so he goes to start and PFT, it backfires and a bunch of white exhaust comes out of the pipe. Being too rich couldn't cause this sudden backfiring could it? I tried starting it a couple times and the same pop happened.