I wanted better performance out of my 68cc motorized bike, so I went and bought delorto clone from Amazon. I also bought some jets for tuning. I put it on the bike with a 60 jet and now I have great top end performance. It goes WAY faster than the stock carb ever got me going. But now the low end performance and idle are terrible. It will keep a high idle for about 6-7 seconds but then the rpm's start going down until it dies. If you give it throttle when it's at low rpm's or when they are dropping, it severally bogs and dies. So you have to feather the throttle just to keep it from dieing. I also tried some bigger jet sizes but they just made it worse at any rpm. I need to sell it so any help is much appreciated. Thanks