Originally Posted by 2door
In the original question your concerns seem to be with what you see in the fuel line and not how the engine is running. Are you having engine problems or simply assuming that the engine is starving due to a partially filled line? There is a lot of misconception regarding the flow required for a small single cylinder 2 stroke engine. Some will tell you that you must have a gusher coming from the fuel tank. Not so. You want a steady flow, not dripping but any steady flow will feed the engine sufficiently. Pay no attention to what you see in the fuel line or transparent filter that you might have. You'll see all kinds of levels and flow depending on several factors such as ambient temperature, throttle position, float level, ability of the tank to vent, etc. Confirm that the tank/cap is venting properly and don't worry about the visual indications.
Also forget any ideas about adding a fuel pump. Any added positive pressure will only force the needle valve open and flood the engine. They are designed for gravity flow only. The float can not apply enough upward force to counteract the pressure of a pump.
I agree however I know that when the fuel line went between my top bar and the lower accent lines, it was getting pinched, and def' starving her for fuel @top speeds, I now have it to the outsid with a better filter and I've been whizzin through the rush hour traffic ever since!