vibrating choke

[beentryin]

my choke just started to when i start getting to top speed the choke will vibrate shut,anyone know of a fix?

 

[AussieSteve]

I assume you're talking about the NT carb for HT engines.
Have you tried tightening the nut on the choke lever pivot?

 

[beentryin]

no its actually a speed carb and yes the nut is tight

 

[AussieSteve]

Maybe you could extend the flat section of the pivot by filing the sides, so that the choke lever seats tighter when the nut is tightened. Hope you know what I mean.
You'd probably only need to remove about 0.020".