Same basic principles apply to the 4081 too! I pulled the white internal cart out of the big cart with tweezers... cut a spring from clicky pen (make sure its a silver spring) spring should be about 3mm from the top, put small peice of polly in top off insert back into the cartridge and your good to go for about 5x longer and no dry hits..
http://www.e-cigarette-forum.com/forum/experiments-equipment/46125-i-call-adp-mod-auto-drip-mod.html
http://www.e-cigarette-forum.com/forum/experiments-equipment/46125-i-call-adp-mod-auto-drip-mod.html