Is it the linkage or the shock bearing i had same problem with mine But it was the shock bearing on mine ..Is it  where  shock open and slides over the linkage because it  takes the same bearing as the 87 to 90 shock bearing. But it is in the linkage instead of the shock like the 87 to 90 models. PART THE OME parts number for the bearing is 62175-00B00 but its like 44 dollars and you have to get 2  oem parts  62657-34A01 which are clips Then you need to dust seal parts number is 62226-28C00    Also you need a  2 Spacer  parts number is 62684-28C10 .You would have more money in buying oem parts for this bearing then going to
Ebay and buying a whole 91 -92 shock linkage kit for your quad.Like i said if your bearing is bad where the shock slides over.You can buy a 87 to 90 shock beaRING KIT OFF EBAY FOR LIKE 20$ or so alot cheaper the going OME parts