you need to talk to Kev about a fuel mod and setting the CO and tickover properly, this will cure/smooth out surging
while the red key is a "must get" item when buying a bike in reality unless you need to reprogram a key its not essential,i have had my XT for 3 years now and I have the red key but it remains in the folder that it came in unused untouched
talk to Kev before you spend any money there is nothing he doesn't know about setting this bike up!