west going hard too fast

[A440A@AOL.COM]

Greetings, 
    In using the West System resin products, I have run into problems with 
even the smallest dose from the mini pumps beginning to set up before I get 
as many bridge holes, etc, filled.  I am  using the 105 Resin and 206 
Hardener.  
    Anyway to slow this down?  
Thanks,
Ed Foote