[Gaz64]

Jon,

Sounds like a majority of your problem is twisted shafts, generally from tightening the lever nuts.

Take all carbs off, back out the idle speed screws and observe the throttle plate balance one carb at time.

You'll quickly see what's going on.

It then becomes a matter of a twist and adjustment of blades within the bores.

Everything to do with throttle control should be on the lever end, nothing on the other end. I also run my carbs with all the speed screws resting of the linkage. I run centre mounted heim jointed linkage, my carbs have stayed perfectly balanced since I fitted them.