Better check your facts. I have two sleds in my garage that prove that statement wrong.
Ok so my calender is of by a year, i can tell time though.You have two 900's in your garage which are 05 and"cleanfire's"(EFI)
As far as facts go EFI has absolutely nothing to do with PERK!
I stand by my original post 500,600,700and 800 liberty twins to present(which by the way this thread was started for) all come with PERC none come with EFI.