Originally Posted by DoucheBag
Description of Failure(s): Bike shuts off when, (20% of the time), coming to a quick stop
This is/was a common fault on XT660s. The explanation was that the idle speed set in the ECU was say 1600rpm, and yet in a low gear, maybe 1st or 2nd when coming to rest, before dipping the clutch your revs would drop below 1600 so the ECU said 'game over' and killed the engine.
The fix IIRC was to reduce the idle by 100 to 1500rpm, which in the case of the XT660 could be done through the instrument panel I think. Either way that seemed to fix it for lots of folk.
I wonder if this is what we are seeing here?