I am having the same problem with the same bike I just bought. + After riding shorts distances (on high idle to prevent stalling) it will not turn over because the battery is drained and need to recharge it again using a battery charger. I'm not sure if the bike is recharging the battery as it should while running. + can't figure out how to adjust the fender so are not touching the tires. I assume "a" screw is the gas flow and "b" is the air flow. when turning counterclockwise they come out more and I can't figure if that is opening the flow more or closing it. I still like this bike and don't regret buying it but hope to ride on it further than my street without worries of making it back home.