As I remember it ;
Drill a 3 mm hole in the airbox takeoff, and in the jet located in the takeoff on the amal valve that goes to the air box.

The hole in the air box on my saff was almost 3 mm (maybe somebody had played with it)

When I tried to bore the jet in the amal valve to 3 mm the jet came out of the amal vale ( talking about the takeoff that connects via a hose to the airbox).
So I ended up putting the hose back on without the jet ......
It helped hesetation a bit!

Now I have an amal valve jet in my ashtry

Cheers Kennert