I finished installing my 2-stroke engine kit I got off ebay and I'm having some trouble firing up the engine and riding for an extended period of time. After I had no success starting the bike up last night, I re-wired it so the green and white wires were grounded. After that, the bike actually fired up and I rode it for about 15 seconds until the engine stopped running. I still heard the engine revving when I throttled, but it didnt power the bike at all. Today, I had no luck starting the bike until I tightened the spark plug, which gave me a few good 30-45 second rides until the engine died again. I am pretty sure that a few tweaks to the carburetor or spark plug will do the trick. If anyone else has had this problem where the bike will ride for about 10-30 seconds and then the engine sputters and stops working, what did you do to fix it? Also, what does the idle screw do, how important is it, and how tight should it be? Where should the choke switch be?