Amal on Thunderbolt.

[A10 JWO]

I have a brand new concentric on my single carb A65 OIF. Running weak, needs choke on to pull. Which notch should the carb needle be on please.

[JulianS]

All the books show needle in position 1.

But you will  need to experiment for best settings, using the Amal tuning guide.

[A10 JWO]

Hi Julian. Just come in from the garage with some success. The main jet on this new carb had some rubbish in it. Could barely see through it. Thread complete