Oh I wish things worked how they were intended. You will quicky trash the timer set up and never use it again, I guarantee.
Most guys use inexpensive digital timers of all sorts that can be bought. The favorite of us out here in LA running modified Shootout Rules are the talking timers, these I buy from Amazon, just search talking timer on Amazon.com, they are great and inexpensive.
Good luck with the plastic gear timer though, I really do hope you find it useful.