That 4-stroke motorized bicycle not firing up? When your magneto wheel and CDI give off a current but the electricity's just not getting to your motor, it's time to replace your spark plug with this 4-Stroke Motorized Bicycle Spark Plug. With a spark plug gap of .6mm (~.024"), this spark plug is designed specifically for 49cc 4-cylinder bicycle engines.
Without a spark the fuel in your motor won't create the explosion needed to move its piston up and down in order for the engine to run properly. When your plug's discolored and not give you a spark, just use a spark plug tool to simply unscrew and remove the plug, then simply install this new spark plug in its place. After your spark plug's replaced just pull the pull start, hit the throttle, and you're on the road in no time.
Part #63 on the 4-Stroke Diagram
This spark plug is good for HuaSheng 4-stroke motors, including Flying Horse and Grubee 4-stroke bicycle engine kits.
Buy a couple the first time I ordered one when i kept on forgetting to turn the choke off and fouled the original :/ Get a couple of them, they're inexpensive when U get them on a flash deal!