79 CB750F. There is a little white plastic (looks like an inline filter) from the vacuum fuel tank cutout switch to the carbs inlet port. It has a directional arrow impressed on it for flow, but it doesn't look like it is doing anything. I blew air through it in both directions. If it is a check valve, it should function only one way correct? Is this part defective? If so, can I just get rid of it?