Son of Magni

BTW, all the L series valve covers are interchangable, so you can't go by that. Use the casting number... SoM

This is also caused by worn throttle shaft bushings. When you let off the gas they don't always return to the same place due to slop in the shaft. There's really nothing you can due about it besides getting newer carb bodies. If you apply a spray on grease at the throttle shaft ends and the problem temporarily disappears you've found your problem. My thoughts on linkage lubrication. The teflon ends on the linkage do not need any lubrication. I find mine sticks the least if I take the linkage apart and clean the joints with break parts cleaner. The only place I use grease is at the carb body and where the linkage shaft rotates in the balance tube mount. SoM