Hi,
Honda has shims for different shafts in all kind of models, they call it thrust washers.
Measure the diameter of the shaft, and look in several part manuals for the right diameter and order them.
For example :
A thrust washer of a honda CB250 with inner diameter of 20 mm, has part number 90458 292 000.
look at (for example only) CMS and find out :
http://www.cmsnl.com/searchparts.php?s_ ... alresults=
normaly these thrust washers are 0.4 / 0.5 /0.6 thick, when you need them to be a little smaller just grind them off.
I make them from coper when thickher than 1 mm, and from steel thinner than 1 mm.
Never make these thrust washers thinner than 0.4 mm, otherwise thesee will collapse.
Jensen