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I'm having some problems with my agility. When there are two persons driving on it, it stalls and after couple second it shuts off completely. Scooter is behaving like he's running out of fuel but there is enough fuel in tank. I cleaned a carb and it didn't help, also changed a spark plug and tried to drive without a vacuum switch, or whatever it's called, which is connected after the tank and before the carb.
This winter this problem had gone and i thought it self repaired. But i was wrong. My money is on ignition system but i'd like to hear your thoughts and a few lines on how to test ignition system precisely what voltages do i need to get.