Mine dies about 75% of the time after a quick deceleration unless I rev the engine when stopping. Even if the engine is hot. It's the only problem I have with the bike.
Mine only does it about 10% of the time so I'm probably not going to worry about it unless it gets really bad.
Also check that the spark plug caps are pushed fully home and seated.
This that not quite make sense, did happen to me some years ago....
Now and then, and
only during a deceleration.....it was running only on three cylinders, when adding throttle again...
the few times this did happen I wasn`t closing in to a roadcross etc. so no need to pull the clutch...
most times this did happen I was going downhill.........so two kicks with the left foot to get some more rpm
and adding good throttle opening.............welcome back #4.
It turned out to be a broken spring at the connector, inside one of the plug caps.....
I don`t say that this is the problem on your bikes, but it could be worth checking.........
Have some experience with loose caps on K`s, but only one time the behaviour has been like this.
Inge K.