Anyone ever changed or drilled out the pilot jet on bike carbs?

My mixture screws are 3 turns atm and still running weak (16 afr)

Worried about unscrewing them until the spring pressure cant hold the screw against the vibrations.

So, its a 38 pilot jet, what does that mean? 0.38mm??

Is a 40 or 42 the next step, say with 1~2 turns out on the screw?

Steve

The pilot air jet needs to be smaller rather than bigger in order to richen the mixture up doesnt it??

Hmm, the little brass jet next to the main jet.

Its got a tiny hole sitting in the fuel and a small emulsifier tube attached

Ah gotcha - i know the bit you mean now sorry. Yeah going bigger should allow more fuel to flow but think you can safely wind out the pilot screw a bit further yet - some of the GSXR600's had the screw 3 1/2 turns out according to the manual (Mikuni carbs)

link to jet supplier anyway - i used to work around the corner from them