I ran out of gas the other day so I stopped and put it on reserve and it still wouldn't start. I thought since the reserve is probably at the bottom of the petcock it might have had something blocking it. I took off the petcock and the on side is just about a 1-1.5" tube/screenfilter sticking up from the petcock. The whole thing was a screen. Is this normal or is mine missing something. I just don't see why they put a reserve on the petcock if the on is basically the same as the reserve but with just a tube/screen sticking up.