I just did cover off timing chain job on my 86 Euro 500 Se(420)Euro engine.The larger bottom rail had deep groves in it was so thin could almost see through it ,all the rails were badly worn, they had 94 stamped on them so guess they were 8 years old.Also changed oil pump chain while had it that far apart.was a time consuming job but feel much better having all new rails as don't know how many miles are on this replacement engine.It runs strong burns no oil,oil is still clean after 1200 miles since change........
William Rogers......