allot of times if im working on an engine that i didnt take apart..like my neighbor had an old yamaha i was rebuilding for him, i went to "yamahapartshouse.com" and looked at the parts fische..when i was working onthe clutch to this bike there was three washers that went to the clutch assembly, two behind and one in front of the basket, because i didnt take this engine apart i didnt know wich one went where, they were all different thicknesses..sooo....i went to the diagram and price listings...RULE OF THUMB ...the more expensive washer/shim will be the thicker one..it helped me out by looking at the prices of the shims and the parts blown up diagram to get the right order in which it was suppose to be assembled..
not sure if that helped at all but thats what i went through a time ago on a "strange" engine,,..good luck man...