Does anyone know about any alternative rubber stoppers for du bro and similiar tanks that won't deteriorate over time? have had problems with old rubber pieces breaking off inside tanks that have been sealed and stored for a while. I was thinking that maybe someone was making these out of silicone like our fuel tubing is but don't know where to look. Otherwise Does anyone know of someplace to get them more than one at a time? Gonna buy at least a dozen

I had the same problems you described. After I aw a Hayes fuel tank, which has an o-ring istead of the large soft rubber seal, I replaced all of my fuel tanks.

They deteriorate over time and it costs little to buy a repair kit from Sullivan to avoid any leakage problems.