Hi. Super newb here. I recently bought a 49CC engine kit from ebay seller boygofast and installed it on my 70's free spirit cruiser. After a good amount of tweaking (tightening the clutch cable, adjusting choke, securing wire connections, etc.), I was finally able to get it going. It seemed to be running OK, but I didn't really ride it around much—just around the block a few times. The next couple of days I had a harder time starting it and/or keeping it running. I read through a number of threads relating to starting problems and noticed there was a decent amount of smoke leaving the exhaust, and thought perhaps the mixture was too rich. So I decided to increase the fuel to 20:1, instead of 16:1. After that it seemed to be running much better. The engine sounded robust and it accelerated great. A lost idle screw and a few days later, I began experiencing similar symptoms as I did before, and now I can't get it to start at all. There were a couple of times after letting up on the clutch that the drive chain and rear wheel would lock up, so I suspected that the engine might be flooded. Accordingly, I pulled out the plug and rode it around with the engine engaged to try and dry things up. Still no go. I replaced the stock plug with an NGK B-4L, though both plugs get spark. Interestingly, there is no visible smoke leaving the exhaust. The kill switch is disconnected, though it doesn't seem to matter if it's connected or not. Any suggestions for an ignorant newcomer?