My overflow drain has gas

[outtafocus]

Originally the stand pipe was as tall as the overflow. I was testing to see if the height of the stand pipe had any thing to do with the burping. It seems this was not the case. I am picking up the new cap tonight and I will also pick up another stick of 1" pvc, I want to redo my return plumbing aswell.

As for the size of the stand pipe vs the bulkhead, it will have to remain as is. That slip to thread adapter is stuck in the bulkhead. When I picked it up, I was testing thread fit by hand and did not tighten at all, but when I went to remove it, it would not come undone and I didnt want to scar my bulkhead so I left it in. Now with it in the overflow I dont have the room to get it out. I am not worried about it.