I'm in the process of rebuilding a dead K100 and decided to strip the fuel stained paint on the tank and bring it down to the aluminum with a lot of clear coat.  Now I've got to get the rubber pad that protects the tank from the seat back on.

Any recommendations about what I should use to stick it back on?

Black Super Weatherstrip and Adhesive, part number 08008, black Gorilla snot by 3M. Or 08001 if you want yellow Gorilla snot. This stuff holds windscreen rubber moulding onto cars. It'll even hold Airhead engine nameplate badges onto the top cover, in spite of the heat.

I will try the black snot, thanks!