I've been having a lot of trouble getting my bike started. This probably is not related to that trouble, but it could be. I have residue around my spark plug. I found this online: "the oil from the plugs two causes 1 is they were never torqued correctly. two is the crush ring, also called a fire ring, is only supposed to be crushed once." I read elsewhere to turn the plug by hand, then torque 1/8 of a turn. Is this correct? I have taken this spark plug out and put it back in before. Is this information about the crush ring accurate? I've never heard this before.