shadow paul

I am building a 3 engine jet, I have engine 1, 2 and 3 engine starters working, now I require engine shut off switches can you tell me which off sets to use I have tried 3590, 3594 3598 but I can't get them to work, I assume I am not giving them the correct offset values for incorrect release values I am very new to FSUIPC so please take it from the start thanks Paul