I have a motorized bicycle with a 2 stroke 66/80cc China girl, slant head, center mount, direct drive, RT carburetor, bottle booster, and expansion pipe from SBP. The bike was running fine until the wire that connects from the CDI to the spark plug cap vibrated loose at the cap and started arcing. I didn't notice that it had happened until the motor started sputtering as if it wasn't getting enough gas, then backfired and died. The arcing melted the plastic part of the spark plug cap dripping melted plastic down the spark plug and onto the head where the spark plug screws in. I replaced the spark plug and the cap with new ones but it still won't run correctly. When I try to start it, it will start for a second but sputters and bogs down at all throttle levels as if it is not getting enough fuel. When I disengage the clutch and take the load off it won't stay going. It's like it tries to start but isn't getting a steady stream of fuel or something. It sputters, jerking forward and back. I took the head, cylinder and piston off and cleaned the piston and head where the spark happens but it had no effect. The needle barring looked fine. What should I check next? I have a new CDI that I was thinking of putting on. It is brand new with a new wire and spark plug cap. Or I was thinking that maybe the problem is the carburetoruretor. Should I try a different jet in my RT carburetor or put my NT carburetor back on and try it? Is the timing off? If so, how do I adjust that? Is the engine history? It's still pretty new with only about 200 miles on it. Could it be something else? Thanks for any advice.
