I have a 150cc coolster. Didn't run when I got it however I know that it runs. Long story short it needed a new carb and ignition coil. And for some reason even with accurate fuel and spark I still can't get it to run. Only if I put a squrit of gas into the cyclinder. I am so confused on why the intake has only one brass nipple. Isn't that a vacuum line? Anyone that can help me diagnose from here I would appreciate it!