Motorcycle Repair: leaking rear main engine seal bmw 1983 r65, excessive blowby, oil leaks

Question
I replaced seal about 1993, lasted2004,leaked after 1st ride 2004, just took apart, could i have gotten bad seal? It was different they said improved.  Any hints for seal, do you ever need a glue, putty, caulk type materiel? Do you recommend a brand? Is there a test for leak beside putting back together and starting, very labor intense.  If oil leaks it ruins the clutch, very expensive. Not ,but if seat had a sratch, how do you seal?  thank you

Answer
It is possible for seals to fail from bad installation
or damaged shaft or poor seal quality. Also, if you
replace it again I would have the bearings checked
to make sure they have proper clearance.
Be careful with caulk or sealant, silicone is slippery
and the seal could pop out. See if there is a factory
approved sealer available. Check your crankcase for
a breather that could be plugged, or excessive
blowby from engine may increase internal pressures.