Code:
on me:*:JOIN:#help: .timerCheck 0 60 CheckIdlealias
alias CheckIdlealias {
  if ($me !isop $chan) && ($idle >= 540) { part $chan }
}

on me:*:PART:#help: .timerCheck off
I forgot to stop the timer once you leave the channel.

Paste this code and it should work fine smile Note that i have named the timers, so this way i can choose which timer to stop.

Tell me if it works.