18-06-20, 08:40 PM
I'm currently running mine with no EXUP valve in. It needed urgent attention and it was quicker (and possibly cheaper!) for me to fit a complete Black Widow system. Servo cables are ty-rapped out of the way. I'll deal with the headers and valve another day.
Also fitted a 4 deg ignition advancer at the same time.
I really can't say that I can tell any difference - pulls just as well low down as before, in fact maybe even better.
So.…….. almost like a oil/tyre/seat/fairing/suspension* thread, everyone's having different results!
(*delete as appropriate)
:lurk