Vacum slide issue

I have a LTD 750 twin -83 with BS34 carbs. In the vacum slide there is a plastic washer keeping the needle in place. From time to time the washer in the left slide moves up about 10 - 15 mm in the slide and the bike starts to run bad. Anyone had tis problem? Thanks i advance.

//Jan

Have you cleaned and checked the throttle and the plastic washer for damage?
What about the spring?
I have never encountered that problem on any of my bikes
/A

Here is a web side that shows the installation of the needle and plastic washer in the slides. Technically impossible that the needle lift up 10 - 15 mm in the slide with the spring/washer on the E-Clip!!! Missing E-Clip or weak spring ???









www.z750twin.de/vergaser.htm

@scubaanders
Neither have I. I tried pods two years ago, runned them for about an hour, then installed the airbox again. After that the washer started moving. It*s actually a quite firm fit in the slide, I have to push hard ti get it all the way down so I just can*t imagine wat's causing it to move.

@Scirocco
It's not just the needle, its the whole washer moving up. Both needle and washer is installed correctly.

I would pull the needle jet if something is in there that let the needle not get full in.
Could it be that the needle is a little bit bent???