I have a china 49cc moterized bike kit. I have been running good for about 6 months. It started to back fire when I got to a sertin speed, now it wont start at all. I replaced the coil. it is getting fuel, the spark plug is wet. I replaced the plug. Regaped the plug. Checked the float. Checked the needle thing on the throttle. I hear the needle is to be on the 2ed something? I Stuck a serwdriver in the plug thing going to the spark plug and I am getting a shock. Can anyone help? Thank you in advance.