osbornk
Old man in the mountains
I wouldn't recommend switching to synthetic. It will find a way to seep through older seals that have no problems keeping normal oil.
Once the seep starts, one has to begin replacing seals.
Jim
I don't you have to replace the seals. I tried synthetic in both an older K bike and an older Airhead. They both started seeping but both stopped when I went back to conventional oil. I sold the K bike but I have still have the airhead and it has been 13 or 14 years since I went back to conventional (and no seeps).