The next thing on the agenda was to slip the GSXR filler into the huge hole we made earlier and then work out a way to seal it all.

Before the filler plate could be welded in, we had to resolve the problem of the drain & overflow tubes. On the GSXR there are two tubes running from the filler cap to the bottom of the tank, as you can see above. in that picture, the "new" filler base is lying upside down in its new home, because that was the easiest way to photograph it.  

One of those drain pipes is to drain any water that might have collected after a rain shower or a bike wash.  The other drains any fuel that has spilled when filling the bike.  That also acts as a breather hose so that as fuel is used, air can get in to replace the volume.

One of the drains was blocked off and the other tube was removed, shortened and brazed back in a slightly different position.

Next, a hole was drilled in the tank tunnel for the drain tube to run through.  Obviously that will have to be sealed around the tube to prevent a massive leakage of fuel onto a hot motor. That would be decidedly sub-optimal.

The filler neck was carefully aligned and welded into place. And just for the record, I never claimed to be a good welder. 

Here you can see the drain tube protruding from the bottom of the tank tunnel awaiting its destiny with the welding torch and brazing rod.

After the filler neck and drain tube had been welded into place and pressure tested for leaks, the hard work of blending it all together to make it look as if it had always been like that began. Filler of choice is high strength glass fiber reinforced body filler (Bondo).  With all the glass fibers, it's quite a different material to work than regular Bondo. It's almost gelatinous when wet, and not too easy to sculpt.

The filler has been rough sanded to the new sleek shape, and the filler cap screwed into place to check fit and gaps around the neck, prior to sealing the tank and taking it to a body painting pro for a nice shiny coat of .................. Wait and see.....