I had to have my rear shock rebuilt when I bought my bike in 97
(probably because the previous owner only put 1,500 mi on it and the
shaft seal dried out). I noticed even then, that the bushings were dry
and already scoring and zirked the top & bottom shock mounts as well as
the knuckle or "L" arm. It is easy to drill and tap a hole in the middle
of the boss that holds the bushing. Zirk fittings are available at any
automotive parts store - the 90* or 45* work best. This past winter, I
borrowed some racing stands from a friend, to completely tear apart the
rear end, as you have to remove the sidestand to get at the rest of the
linkage. However, I found that these others were needle bearings, which
Zirk'g won't help. But packing them good with grease will last a long
time vs. solid bushings.
Like many have attested to on the list, a little grease goes a long way
to prevent busings turning to powder. Now I just give them a shot every
time I change oil.
- -- 
Dave Biasotti // Fremont, CA
Dir of Procurement, LSI Logic Corp.
biasotti@flash.net
'83 Honda 650 Turbo // '93 Yamaha GTS1000