Originally Posted by Notaduke
Great, thanks. That solves that part of the puzzle, although this pie pan with a pie in it seems like a pretty bizarre piece of engineering.
I guess I can't say with 100% certainty until I get a new screen installed, but it seems to me that losing that screen has an amazingly big impact on the backfire situation. Must be right on the edge with it installed.
I think with stock FI it will run leaner which will make the back fire worst w/o screen - I read that. With JD tuner screen can be removed. From what I understand that (screen) is not part of the spark arrestor.