Midrange needle falling out?

Hi all,
Have a problem with my older Savage XL 5.9, the midrange needle constantly falls out.
This last time it was lost and I just ordered another one.
I see on HPI's website that the newer 5.9 carby has an additional screw that looks like it locks in the midrange needle, mine definitely doesn't have this screw.
Can anyone confirm if this is what that screw does?
If so, I might drill and tap my carb for a setscrew install, sick of trying to find the thing after it falls out.

Cheers.

Could you put some high temperature silicone on it? Looks to me that would help hold it and seal it.

EUGENE477 said:

Could you put some high temperature silicone on it? Looks to me that would help hold it and seal it.

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Have tried a dab of silicon, loktite and other thread lockers. The screw simply unscrews itself no matter what.
Maybe this is why the new carbs have this additional screw!?

Cheers.

Do the threads seem to be fine?

EUGENE477 said:

Do the threads seem to be fine?

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Yes, the threads appear undamaged, I think it's caused by the o-ring being crushed over time allowing the screw to unwind with engine vibration.

Cheers.