B pipe clogged

[Half flip95]

I came across an old 2 screw factory head pipe. the bottom hole is clogged. any hints on getting it unclogged? I tried all the obvious stuff, its sitting in a gas bath right now

 

[just joe]

Is it the very bottom hole that doesn't have a adjustment screw? If so, most people fill this hole as it lets too much water into the pipe. So it may be clogged with JB weld