throttle cable

[Phil]

Hello, I know this is probably a dumb question, but how do
I keep the cable end housing in the throttle control twist grip,
I cant keep the end from slipping out a little evertime I let off the
throttle, I'm not referring to the actual cable, but the cable housing's end, is the jam nut supposed to collapse around
the end and hold it in place? Any tips would be appreciated?

[ruppparts]

tighten the inner wire...take out all the slack when throttle twist grip is closed and engine linkage is at an idle