The washers want to go onto the studs before the springs, spring cups and nuts. The nut
goes right through the spring cup and clamps the washer to the clutch body. This stops
the nut from screwing down quite so far and compressing the spring quite so much, hence
softer clutch action and, sometimes more likelyhood of clutch slip. The clutch action
will still be horrible however if the cable route is wrong or the cable itself is rubbish.
I use do-it-yourself nylon-lined cables on my four-strokes and the improvement over over-the-counter
non-lined cables is considerable.