Shubova,
I run an OS 120 in mine, I made a 90 degree bend just long enough to grip and to see, but instead of drilling a hole in the cowl, I made a small slit that is
as long as the small "handle" part of the extension. When you need to remove the cowl you have to align the wire so it slips through the slit in the cowl, but if
you remember how much and what direction you turned the needle, you can just turn it back when the cowl is on.
On my WACO, I was able to solder a piece of cable between the extension and the needle valve, and the cable let me exit behind the cowl on that one.
Sorry my explanation is not clear, I' having a hard time describing how I bent a piece of wire [X(]