"S" or "T"? If it's associated with Mr. Bertrand's suspicion, go up/down a gear and see if it makes a difference. I don't mind the throttle, but sometimes my gear/speed are in the perfectly wrong place, and it'll surge until I switch gears/speed.
That made a big difference in idling on my bike. I never noticed a surge but had a few oopsee stalls at lights before the sync. It really does effect the low rpm fueling for sure.