Just put together an 80cc kit and the motor won't run on idle and it runs kind if rough.. Once it gets going it smooths out, but if I slow down or com to a stop the motor starts running rough-- if I stop completely the motor idles for a couple seconds and dies.. I have not adjusted the carb in any way, and the kit's instructions didn't have any info on adjusting the carb.. Also, there is a bit of oil leaking out between the muffler and the block-- I tightened it down but I'm afraid to tighten it any more because I don't want to strip out the threads in the aluminum block... Any help would be greatly appreciated!!!