My problem was our predator 50 would start just fine when cold, but after it was good and warm and shut off it didn't want to start again until it cooled off. I read lots of posts on here and checked out lots of possible issues and finally found my problem today. It's the spark plug wire cap, something, I suspect the metal that grabs the top of the plug, is expanding when it gets hot and not making perfect contact. Three times in a row today when my daughter would shut off the bike and I went to restart, it wouldn't start all. What I did was pull the wire cap off and push it back on and it fires right back up. Normally I would have pissed around for a half an hour checking this that and the other, and thought I had a real problem, this only takes 2 seconds and it's back in action. I wonder how many times I've read posts about guys saying they are eating plugs like crazy are actually having this problem and replacing good plugs one after another. I will first pinch the female connector in the cap a little to see if that cures it, if not I'll order a new coil to plug wire. But I hope this solves some of you guys / gals problems too. Good luck.