Re: Too much backing line or Too much fly line?
On my reels, I only run as much backing so it won't rub the fly line on the reel.
The best way I found, is to spool the fly line first, then spool the backing on top. When it gets close, cut the backing. Unspool, and re-spool the right way...backing then fly line.
The problem with just getting close, when you reel in fast, the line doesn't always distribute evenly, so there's more of a chance of the fly line rubbing. So I keep the backing length short enough so that never happens.