Is there anyway to edit the teleporter link-to-mainframe time?

whenever I place non zombie actors in my map I start out with 8 grenades, and anytime I use a grenade it uses two, but every round I get four grenades. 

I made a catwalk and put pathnodes on the catwalk and the ramp leading up to the catwalk, but whenever I go up there the zombies stop and don't know what to do. Any help on how to make the zombies go up there will be greatly appreciated.