I have done my conversion from flat tops to SUs on my 1973 240z. I have removed the air pump and the egr valve and cleaned it all up with a 240 style balance tube. I was wondering for the other Z owners who have done this same conversion what mixture setting they run. I know the Ztherapy video says around 2 1/2 out. I also have upgraded with msd ignition with the zx dizzy. I am concerned that I am running rich when I regapped my spark plugs the other day and they were all black. I also am only getting about 19 mpg. What setting do you run on your SUs?

-thanks

The number of turns we all use will vary depending upon the exact float level per carb. For example, my carbs are about a half a turn different from front to rear. No two cars are likely to have the same settings, even if they are identical set-ups. The 2.5 turns out is a convenient starting point, you need to fine tune both carbs independently from there.

Reclaton , There is a article on the adjusting the SUs and I think you will find it if you do a search for adjusting SUs. Arne is correct the 2 1/2 turns is a good starting point to get you up and running . Do you have a flow meeter to balance the two carbs air flow ? I bought mine at the local parts store for about $25.00 , they have a performance section . mine is a uni-sen and packaged by Edelbrock . A device to balance the carbs is a must . I does sound like you are running rich , you should be getting up in the 20s for mileage . If you do replace the needles , get #54s , I think you will be satisfied with these . These are still available from Nissan . But do check the search because there is a step by step on adjusting these carbs. Gary I just tried to find my article on this and couldent. Send me a PM on this and I will go over it with you .

The carbs I bought were from Z therapy, and I installed them in late April I think. I do have the flowmeter and can balance them, but don't you only use it when using the idle screws? How do you adjust the mixture independently?

No. You use the flowmeter to help adjust both the mixture and the idle screws. Then once you have the idle right, you move to high rmp ~3000 and adjust the balance screw. Do you have the tape from Ztherapy? If not, I can explain a bit more since I just went through this. Let me know.

Bill