My Cuda has about 400 miles on it, everything including the Holleys are new. When I first started last summer I was getting a severe surge going down the highway and was told to bump the jets from 62 to 69. Within a week I was getting backfire through the exhaust on excelleration and the plugs were very black. I was then told to drop down to 67's and still could not keep the plugs clean but the surging pretty much went away and I was still getting backfire so last fall I changed to 64's on the jets and have not had a chance to drive the car but I started it last week and noticed a lot of black fluid comming out the tail pipe when I first started it. Do you think this was stored or do I need to go down to 63's for jets? On everyones advice I have replaced everything electrical including the pointless ignition. The one thing I have noticed is that I am able to get idle adjustment on the center carb now but with the two outboards I need to turn the bottom two screws in all the way for the car to idle properly. I was told that I should put my fingers over the two bleed holes and if adjusted properly there would be no change in idle speed. I am not able to do that and I do not know why. If there is anyone from central Wisconsin reading this and they know of a good six pack person in the area please let me know because it seems I can not get this on my own.

Have you set you float levels? Where are they set at? What is you initial and total timing set at? Have you checked for vacumn leaks?

there have been at least one post, (i'm sure many), on the board about how to tune 6 pak carbs, detailed step by step.

probably would be a good idea to search for one of those and go through it from step one.

I am using 65s in the center and 80s in the outboards with Promax jettable plates. My mixture screws in the center are 1 1/2 out and the outboards are 1/2 out. I agree. Do a search and check in the archives and you will find alot of good tips on tuning a 6 pack.

Hi has the carbs been siting for long time and have cork gaskets change them & ck power valve if it backfires it can make a hole in the diaphragm. will let fuel leak by in to intake

floats are set at bottom of screw holes, timing is 10 degrees BTC and checked for vacuum leaks a dozen times

the gaskets are not cork and the carbs are new. I have not checked the power valve but it is not backfiring through the carb, it is out the tail pipe

If it is out of the tailpipe, many you need more timing. I have mine set at 14 with 35 total.