Hi Alan
As far as I know the carburettor fitted to the S and T6 models and derivatives was unique to these Douglas models. The needle is very short. Some years ago Doug Kephart approached the original Amal works and was given two drawings for the needle, one was for the needle for new production, the other for modification of an existing needle used on other models. As Spares Secretary for the LDMCC at the time using these drawings I had a batch of needles made for the Club spares stock. I had them made by Martyn Bratby, well known carburettor specialist and I believe he kept some for his own use. I cannot help with the jet but Martyn may be able to advise.
Chris.
