The first time I put the bike back together it ran like a champ. Then, while riding it in a parking lot, I noticed a speed bump at the last minutes, slammed the brakes and the engine died. I didn't hit the speed bump, i stopped before it. But I had to try 3 or 4 times, after giving it a minute or so, to get it started again. I cleaned out the carbs again and it still does it. Looks like it starts to do it after a few minutes of riding. I don't have an air filter and I cleaned the carbs again... Anyone know what might be causing this?