It's been a while since I've been here so I hope I'm not repeating an already asked Question. I'm sure someone knows what could make a coil go bad. My bike "80cc" two stroke had an evolving spark problem, it would intermittently stop running, only being turned over by forward motion . For a while this was occassional but eventually lost all spark. I pirated a coil off one of my other engines but now it has begun doing the same thing. It took a lot less time to happen this time. The engine has 2000+ miles,and the coil I removed looked slightly oily. I wondered if oil on the coil could impede the electrical function? There are no obvious leaks that could direct oil onto the coil so I just don't know . Any input from the real pros would be much appreciated. thanks John