The Siren Board

I have a neighboring fire company that has one of these Zenith Controls timers controlling their siren. They'd like the overall cycle time reduced....currently this one is the usual 8 seconds on/4 off over a two minute period much like a PGA timer. Outside of telling them to get a whole new timer, is there any way to go the simple route first, and take the current cams out and cut new ones to replace them with? Or are those permenantly in there? Thanks!

I can't speak from personal experience, but those cams look like they are likely removable, given there is hex screws separating them. A