79 Triumph Spitfire 1500 Zenith Stromberg 150CD4T

The adjusting tool and the adjustment in this video. Counter-clockwise on the allen leans the mixture, needle goes down. Clockwise enriches the mixture, needle goes up. That was confusing some owners, how does it do that? so I remove the top of the Zenith Stromberg and the metering needle, to show how it works. I found out the high elevation metering needle, a 45M, is a thicker needle to restrict the fuel flow from the jet, so someday I will see how my engine runs with that needle. The jet is the 0 .1000" size. If the picture looks different from your 150CD4T with a water choke, I removed mine and fitted a cable pull.