MG Car Repair: MGB idle speed, mgb roadster, mirror images

Question
Hello Barrie,

I'm curently working on a 1965 MGB roadster and I would likt to understand why the the front jet and the rear jet on the HS4 are different .The lenght of the "pink" one is longer than the "green" one . Therefore my front carburator is always rich .
Am I somewhere wrong and the explanation of this difference would be appreciated ...

Thanks and regards,

Thierry

Answer
Hi Thierry.  The two jets should be mirror images of each other.  In particular, the brass jets should be identical in length.  I just measured a pink one, and it is 35mm in length.

They may be different heights inside the carburetters, because the adjusting nut will alter the height.  The higher they are, the weaker the mixture.