Ok, I posted a thread like this about a week ago but since some people on here don't know how to control themselves and their opinions the Mods deleted my thread. So here I go again and hopefully it won't be deleted. I've got a 66cc SkyFire hooked up to my Schwinn. Has about 300 miles on it and until recently I've ran into a problem. I used regular 2 stroke oil in my mix at about 28:1 before I switched over to Opti-2 at around 100:1. After going through a tank and a half I started to run into a weird problem. I will be going at a good cruising speed at about 30mph and the engine cuts off all power for about 1/2 a second. Then immediately after that it shoots me right back up to 30mph. Once this started to happen often, I waited for it and immediatly held the clutch in just as soon as it did happen and the engine would just start racing. I was giving no throttle but it was doing this by itself. Now I'm not asking for your opinion of the Opti or any synthetic oil. I just put that out there as reference. Any ideas what could be causing this? BTW, I checked my connections and magneto and everything seemed to be fine.