BTW Gary, if the car is running normally except this, I can almost guarantee it is neither timing nor valves. You may need to adjust them at some point, but, timing and valves don't really unadjust themselves. To get into that is to make it all too complicated. Deal with one variable at a time!!!! (don't ask me how I know)
Doc gives good advice but, (without insulting your intelligence) you might be asking yourself, what is the bridge? It is that part of the carb between the air intake and the manifold. So, there are two ways to measure the needle placement. 1. The typical way is the number of "flats" on the nut on the bottom - what you have already been adjusting. Each flat is one flat edge of that nut.
2. Distance from the bridge. To do this, take the bell of the top of the carb, remove the "sleeve and needle" so that you can look down into the carb itself. The brass ring in the middle is where the needle. By turning the nut below, you can bring the mechanism up flush with the bridge (it will make sense) by turning it anti clockwise. Then, as doc says, turn one and one half turns clockwise to get you in the ballpark. (this corresponds to 60-80 thou if you have a caliper). Reassemble the carb. (this is a good time to make sure there is oil in the bell - use engine oil for now) and fire it up. Assuming it runs, take it out, run it for a few miles, come home, when you pull into the driveway, shut off the car and coast to a stop. (don't let it idle) pull the plugs and see the colour. If black, turn the nut one flat to the right (anti clockwise) clean the plug and go drive again. Same drill till they look the right colour. Then go buy a new set of plugs, make sure they are gapped right, install them and drive the wheels off. You are close I promise you. keep calm and carry on.