Sounds like you fixxed the problem. But for future reference, If the air bubbles are in the line going from the needle to the carb ONLY, then there is an air leak in the fuel line itself, the o-rings that are on the needle are leaking or one of the fitings are loose.

This is a pressurized system, and the only place that will have negative pressure is from the needle valve forward.

If your fuel line was leaking between the tank and the needle valve it would show up as fuel leaking instead of bubbles. If you have bubbles in the line from the tank to the needle valve you have vibration problems with a full tank because the pickup tube would be fully submersed.