Any ideas what kind of oil filter is best for a M-12 two cylinder diesel? Also, has anyone experienced that the Hobbs hour meter runs continuously when the ignition is left on? My 1983 E28+ shows 4000 hours but I cant believe it, she runs like a swiss watch even though it is ocean water cooled. I use Salt-Away and now need to do an annual oil change,,,,,what type of oil is recommended?